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1. Trophic cooperation promotes bacterial survival of Staphylococcus aureus and Pseudomonas aeruginosa

Author

Paul Briaud, Sylvie Elsen, Karen Moreau, Anne Doléans-Jordheim, François Vandenesch, Sylvère Bastien, Laura Camus, Pathogénie des Staphylocoques – Staphylococcal Pathogenesis (StaPath), Centre International de Recherche en Infectiologie (CIRI), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Pathogenèse bactérienne et réponses cellulaires (PBRC), Centre National de la Recherche Scientifique (CNRS)-Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Institut des Agents Infectieux [Lyon] (IAI), Hospices Civils de Lyon (HCL), Elsen, Sylvie, Centre International de Recherche en Infectiologie - UMR (CIRI), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Staphylococcus aureus, Cystic Fibrosis, Context (language use), intercation, medicine.disease_cause, Microbiology, Cystic fibrosis, Article, Transcriptome, 03 medical and health sciences, chemistry.chemical_compound, medicine, Bacteriology, Humans, Pseudomonas Infections, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, 0303 health sciences, biology, 030306 microbiology, Pseudomonas aeruginosa, Catabolism, Acetoin, coexistence, Staphylococcal Infections, biology.organism_classification, medicine.disease, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, chemistry, acetoin catabolism, Biofilms, Microbial Interactions, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Bacteria
Abstract

In the context of infection, Pseudomonas aeruginosa and Staphylococcus aureus are frequently co-isolated, particularly in cystic fibrosis (CF) patients. Within lungs, the two pathogens exhibit a range of competitive and coexisting interactions. In the present study, we explored the impact of S. aureus on the physiology of P. aeruginosa in the context of coexistence. Transcriptomic analyses showed that S. aureus significantly and specifically affects the expression of numerous genes involved in P. aeruginosa carbon and amino acid metabolism. In particular, 65% of the strains presented considerable overexpression of the genes involved in the acetoin catabolic (aco) pathway. We demonstrated that acetoin is (i) produced by clinical S. aureus strains, (ii) detected in sputa from CF patients, and (iii) involved in P. aeruginosa’s aco system induction. Furthermore, acetoin is catabolized by P. aeruginosa, a metabolic process that improves the survival of both pathogens by providing a new carbon source for P. aeruginosa and avoiding the toxic accumulation of acetoin on S. aureus. Due to its beneficial effects on both bacteria, acetoin catabolism could testify to the establishment of trophic cooperation between S. aureus and P. aeruginosa in the CF lung environment, thus promoting their persistence.

Published
2020
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2. ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo

Author

Stéphanie Bouillot, Viviana Job, Vincent Deruelle, Philippe Huber, Alice Berry, A.P. Maillard, Sylvie Elsen, Groupe Pathogenèse Bactérienne et Réponses Cellulaires / Bacterial Pathogenesis and Cellular Responses Group (IBS-PBRC), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), ANR-15-CE11-0018,HemoPseudo,Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence(2015), Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Biologie du Cancer et de l'Infection (BCI )

Subjects
Cyclic di-GMP, two-partner secretion, Health, Toxicology and Mutagenesis, Bacterial Toxins, Virulence, Enzyme-Linked Immunosorbent Assay, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Toxicology, Article, 03 medical and health sciences, chemistry.chemical_compound, Mice, Bacterial Proteins, Animals, Secretion, Pseudomonas Infections, Cyclic GMP, 030304 developmental biology, 0303 health sciences, Pore-forming toxin, 030306 microbiology, Chemistry, toxin dosage, Cell Membrane, Transporter, c-di-GMP, 3. Good health, Cell biology, Pseudomonas aeruginosa, Second messenger system, Medicine, Bacterial outer membrane, Intracellular, bacterial pore-forming toxin
Abstract

ExlA is a highly virulent pore-forming toxin that has been recently discovered in outlier strains from Pseudomonas aeruginosa. ExlA is part of a two-partner secretion system, in which ExlA is the secreted passenger protein and ExlB the transporter embedded in the bacterial outer membrane. In previous work, we observed that ExlA toxicity in a host cell was contact-dependent. Here, we show that ExlA accumulates at specific points of the outer membrane, is likely entrapped within ExlB pore, and is pointing outside. We further demonstrate that ExlA is maintained at the membrane in conditions where the intracellular content of second messenger cyclic-di-GMP is high, lowering c-di-GMP levels enhances ExlB-dependent ExlA secretion. In addition, we set up an ELISA to detect ExlA, and we show that ExlA is poorly secreted in liquid culture, while it is highly detectable in broncho-alveolar lavage fluids of mice infected with an exlA+ strain. We conclude that ExlA translocation is halted at mid-length in the outer membrane and its secretion is regulated by c-di-GMP. In addition, we developed an immunological test able to quantify ExlA in biological samples.

Published
2021
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3. Chimeric Protein–Protein Interface Inhibitors Allow Efficient Inhibition of Type III Secretion Machinery and Pseudomonas aeruginosa Virulence

Author

Rossimiriam Pereira de Freitas, Yung-Sing Wong, Aline Thomas, Sophie Plé, Younes Bouzidi, Antoine Fortuné, Caroline Barette, Flaviane Francisco Hilário, Ina Attrée, Marie-Odile Fauvarque, Tuan-Dung Ngo, Eric Faudry, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Département de pharmacochimie moléculaire (DPM ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Genetics and Chemogenomics (GenChem), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Universidade Federal de Minas Gerais [Belo Horizonte] (UFMG), Universidade Federal de Ouro Preto (UFOP), Associations 'Vaincre la mucoviscidose' and 'Gregory Lemarchand', AVIESAN T3SS (ANR PRP1.4), GIS-IBiSA and ChemBioFrance, Froggy platform of the CIMENT infrastructure (https://ciment.ujf-grenoble.fr), which is supported by the Rhône-Alpes region (GRANT CPER07_13 CIRA), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), ANR-15-CE11-0018,HemoPseudo,Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence(2015), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), ANR-10-LABX-0056,OSUG@2020,Innovative strategies for observing and modelling natural systems(2010), ANR-10-EQPX-0029,EQUIP@MESO,Equipement d'excellence de calcul intensif de Mesocentres coordonnés - Tremplin vers le calcul petaflopique et l'exascale(2010), Faudry, Eric, Grenoble Alliance for Integrated Structural Cell Biology - - GRAL2010 - ANR-10-LABX-0049 - LABX - VALID, Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence - - HemoPseudo2015 - ANR-15-CE11-0018 - AAPG2015 - VALID, Grenoble, une chimie bio-motivée - - ARCANE2011 - ANR-11-LABX-0003 - LABX - VALID, CBH-EUR-GS - - CBH-EUR-GS2017 - ANR-17-EURE-0003 - EURE - VALID, Innovative strategies for observing and modelling natural systems - - OSUG@20202010 - ANR-10-LABX-0056 - LABX - VALID, Equipements d'excellence - Equipement d'excellence de calcul intensif de Mesocentres coordonnés - Tremplin vers le calcul petaflopique et l'exascale - - EQUIP@MESO2010 - ANR-10-EQPX-0029 - EQPX - VALID, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
0301 basic medicine, [SDV]Life Sciences [q-bio], Protein subunit, 030106 microbiology, Virulence, hybrid molecules, medicine.disease_cause, Type three secretion system, Microbiology, 03 medical and health sciences, medicine, antivirulence, Secretion, biology, protein−protein interface inhibitors, Chemistry, Toxin, Pseudomonas aeruginosa, bacterial resistance, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Fusion protein, Type III secretion system, 030104 developmental biology, Infectious Diseases, click chemistry, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Bacteria
Abstract

International audience; Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen naturally resistant to many common antibiotics and acquires new resistance traits at an alarming pace. Targeting the bacterial virulence factors by an antivirulence strategy, therefore, represents a promising alternative approach besides antibiotic therapy. The Type III secretion system (T3SS) of P. aeruginosa is one of its main virulence factors. It consists of more than 20 proteins building a complex syringe-like machinery enabling the injection of toxin into host cells. Previous works showed that disrupting interactions between components of this machinery efficiently lowers the bacterial virulence. Using automated target-based screening of commercial and in-house libraries of small molecules, we identified compounds inhibiting the protein-protein interaction between PscE and PscG, the two cognate chaperones of the needle subunit PscF of P. aeruginosa T3SS. Two hits were selected and assembled using Split/Mix/Click chemistry to build larger hybrid analogues. Their efficacy and toxicity were evaluated using phenotypic analysis including automated microscopy and image analysis. Two nontoxic hybrid leads specifically inhibited the T3SS and reduced the ex vivo cytotoxicity of bacteria and their virulence in Galleria mellonella.

Published
2019
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4. MagC is a NplC/P60‐like member of the $\alpha$‐2‐macroglobulin Mag complex of $Pseudomonas\ aeruginosa$ that interacts with peptidoglycan

Author

Ina Attrée, Andréa Dessen, Daniel M. Trindade, Carlos Contreras-Martel, Pauline Macheboeuf, Samira Zouhir, Brazilian Biosciences National Laboratory (LNBio), National Center for Research in Energy and Materials, Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Pathogenèse bactérienne et réponses cellulaires (PBRC), Centre National de la Recherche Scientifique (CNRS)-Biologie du Cancer et de l'Infection (BCI ), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM), ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), Groupe Pathogenèse Bactérienne et Réponses Cellulaires / Bacterial Pathogenesis and Cellular Responses Group (IBS-PBRC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)

Subjects
Operon, medicine.medical_treatment, [SDV]Life Sciences [q-bio], Biophysics, Peptidoglycan, Calorimetry, medicine.disease_cause, Crystallography, X-Ray, Biochemistry, 03 medical and health sciences, chemistry.chemical_compound, Bacterial Proteins, Structural Biology, Genetics, medicine, Amino Acid Sequence, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, Protease, Sequence Homology, Amino Acid, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Pseudomonas aeruginosa, 030302 biochemistry & molecular biology, Isothermal titration calorimetry, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Cell Biology, Pregnancy-Associated alpha 2-Macroglobulins, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Macroglobulin, chemistry, Macroglobulins, Ultracentrifugation, Function (biology), Protein Binding
Abstract

International audience; Bacterial $\alpha$-2 macroglobulins (A2Ms) structurally resemble the large spectrum protease inhibitors of the eukaryotic immune system. In $Pseudomonas\ aeruginosa$, MagD acts as an A2M and is expressed within a six-gene operon encoding the MagA-F proteins. In this work, we employ isothermal calorimetry (ITC), analytical ultracentrifugation (AUC), and X-ray crystallography to investigate the function of MagC and show that MagC associates with the macroglobulin complex and with the peptidoglycan (PG). However, the catalytic residues of MagC display an inactive conformation that could suggest that it binds to PG but does not degrade it. We hypothesize that MagC could serve as an anchor between the MagD macroglobulin and the PG and could provide stabilization and/or regulation for the entire complex.

Published
2021
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5. Metabotypes of Pseudomonas aeruginosa Correlate with Antibiotic Resistance, Virulence and Clinical Outcome in Cystic Fibrosis Chronic Infections

Author

Robert A. Quinn, Tuan-Dung Ngo, Claire Léger, Oriane Moyne, Ina Attree, Dalil Hannani, Samuel Terrier, Sarah Huot-Marchand, François Fenaille, Eric Faudry, Caroline Plazy, Florence Castelli, Julien Boccard, Bertrand Toussaint, Dominique J. Bicout, Audrey Le Gouellec, Boubou Camara, Benoit Cournoyer, Max Maurin, Translational Innovation in Medicine and Complexity / Recherche Translationnelle et Innovation en Médecine et Complexité - UMR 5525 (TIMC ), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Médicaments et Technologies pour la Santé (MTS), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Genève (UNIGE), Centre Hospitalier Universitaire [Grenoble] (CHU), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Pathogenèse bactérienne et réponses cellulaires (PBRC), Centre National de la Recherche Scientifique (CNRS)-Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Translational microbial Evolution and Engineering (TIMC-TrEE), Université Grenoble Alpes (UGA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Pathogénie bactérienne et réponses cellulaires, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Michigan State University [East Lansing], Michigan State University System, Université de Genève = University of Geneva (UNIGE), Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), and ATTREE, Ina

Subjects
0301 basic medicine, LC-HRMS, P. aeruginosa, Endocrinology, Diabetes and Metabolism, polyamines, 030106 microbiology, Ala-Glu-mesodiaminopimelate, lcsh:QR1-502, Virulence, medicine.disease_cause, Biochemistry, Cystic fibrosis, [SDV.MHEP.PSR]Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, Article, lcsh:Microbiology, cystic fibrosis, 03 medical and health sciences, Metabolomics, Antibiotic resistance, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, medicine, Molecular Biology, Pathogen, ddc:615, Pseudomonas aeruginosa, business.industry, multiscale data analysis, medicine.disease, Phenotype, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, metabolomics, 3. Good health, 37 polyamines, 030104 developmental biology, Chronic lung infections, Immunology, [SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases, [SDV.MHEP.PSR] Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, business
Abstract

Pseudomonas aeruginosa (P.a) is one of the most critical antibiotic resistant bacteria in the world and is the most prevalent pathogen in cystic fibrosis (CF), causing chronic lung infections that are considered one of the major causes of mortality in CF patients. Although several studies have contributed to understanding P.a within-host adaptive evolution at a genomic level, it is still difficult to establish direct relationships between the observed mutations, expression of clinically relevant phenotypes, and clinical outcomes. Here, we performed a comparative untargeted LC/HRMS-based metabolomics analysis of sequential isolates from chronically infected CF patients to obtain a functional view of P.a adaptation. Metabolic profiles were integrated with expression of bacterial phenotypes and clinical measurements following multiscale analysis methods. Our results highlighted significant associations between P.a &ldquo, metabotypes&rdquo, expression of antibiotic resistance and virulence phenotypes, and frequency of clinical exacerbations, thus identifying promising biomarkers and therapeutic targets for difficult-to-treat P.a infections

Published
2021
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6. Bacterial behavior in human blood reveals complement evaders with some persister-like features

Author

Stéphane, Pont, Nathan, Fraikin, Yvan, Caspar, Laurence, Van Melderen, Ina, Attrée, François, Cretin, Pathogenèse bactérienne et réponses cellulaires (PBRC), Centre National de la Recherche Scientifique (CNRS)-Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Pathogénie bactérienne et réponses cellulaires, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université libre de Bruxelles (ULB), Translational Innovation in Medicine and Complexity / Recherche Translationnelle et Innovation en Médecine et Complexité - UMR 5525 (TIMC ), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Fondation Grenoble INP, Centre Hospitalier Universitaire [Grenoble] (CHU), Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications Grenoble - UMR 5525 (TIMC-IMAG), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), and ATTREE, Ina

Subjects
Acinetobacter baumannii, Physiology, Complement System, Bacteremia, Pathology and Laboratory Medicine, Biochemistry, [SDV.IMM.II]Life Sciences [q-bio]/Immunology/Innate immunity, White Blood Cells, Antibiotics, Animal Cells, Immune Physiology, Medicine and Health Sciences, Biology (General), Pathologie maladies infectieuses, Complement Activation, Immune System Proteins, Antimicrobials, Pseudomonas Aeruginosa, Drugs, Bacterial Infections, Body Fluids, Bacterial Pathogens, Klebsiella pneumoniae, Blood, Medical Microbiology, Anatomy, Pathogens, Cellular Types, Research Article, Lysis (Medicine), Burkholderia, QH301-705.5, Immune Cells, Immunology, Microbial Sensitivity Tests, Microbiology, Blood Plasma, Pseudomonas, Microbial Control, Tissue Repair, Escherichia coli, Humans, Pseudomonas Infections, Microbial Pathogens, [SDV.IMM.II] Life Sciences [q-bio]/Immunology/Innate immunity, Yersinia enterocolitica, Pharmacology, Blood Cells, Bacteria, Organisms, Biology and Life Sciences, Proteins, Complement System Proteins, Cell Biology, RC581-607, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Immune System, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Immunologic diseases. Allergy, Physiological Processes, Microbiologie et protistologie [bacteriol.virolog.mycolog.]
Abstract

Bacterial bloodstream infections (BSI) are a major health concern and can cause up to 40% mortality. Pseudomonas aeruginosa BSI is often of nosocomial origin and is associated with a particularly poor prognosis. The mechanism of bacterial persistence in blood is still largely unknown. Here, we analyzed the behavior of a cohort of clinical and laboratory Pseudomonas aeruginosa strains in human blood. In this specific environment, complement was the main defensive mechanism, acting either by direct bacterial lysis or by opsonophagocytosis, which required recognition by immune cells. We found highly variable survival rates for different strains in blood, whatever their origin, serotype, or the nature of their secreted toxins (ExoS, ExoU or ExlA) and despite their detection by immune cells. We identified and characterized a complement-tolerant subpopulation of bacterial cells that we named “evaders”. Evaders shared some features with bacterial persisters, which tolerate antibiotic treatment. Notably, in bi-phasic killing curves, the evaders represented 0.1–0.001% of the initial bacterial load and displayed transient tolerance. However, the evaders are not dormant and require active metabolism to persist in blood. We detected the evaders for five other major human pathogens: Acinetobacter baumannii, Burkholderia multivorans, enteroaggregative Escherichia coli, Klebsiella pneumoniae, and Yersinia enterocolitica. Thus, the evaders could allow the pathogen to persist within the bloodstream, and may be the cause of fatal bacteremia or dissemination, in particular in the absence of effective antibiotic treatments., Author summary Blood infections by antibiotic resistant bacteria, notably Pseudomonas aeruginosa, are major concerns in hospital settings. The complex interplay between P. aeruginosa and the innate immune system in the context of human blood is still poorly understood. By studying the behavior of various P. aeruginosa strains in human whole blood and plasma, we showed that bacterial strains display different rate of tolerance to the complement system. Despite the complement microbicide activity, most bacteria withstand elimination through phenotypic heterogeneity creating a tiny (

Published
2020
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7. The PopN gate-keeper complex acts on the ATPase PscN to regulate the T3SS secretion switch from early to middle substrates in Pseudomonas aeruginosa

Author

Michel Ragno, Charles M. Stopford, Eric Faudry, Arne Rietsch, Alexandra Kraut, Caroline Perdu, Bakhos Jneid, Tuan Dung Ngo, Yohann Couté, Julia Novion Ducassou, Ina Attrée, Pathogenèse bactérienne et réponses cellulaires (PBRC), Centre National de la Recherche Scientifique (CNRS)-Biologie du Cancer et de l'Infection (BCI ), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Etude de la dynamique des protéomes (EDyP ), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, ANR PRP1.4 AVIESAN T3SS, Association Vaincre la Mucoviscidose, Association Grégory Lemarchal, ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), ANR-15-CE11-0018,HemoPseudo,Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence(2015), ANR-10-INBS-0008,ProFI,Infrastructure Française de Protéomique(2010), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)

Subjects
Virulence Factors, ATPase, Microscale thermophoresis, Type three secretion system, Protein–protein interaction, Substrate Specificity, 03 medical and health sciences, 0302 clinical medicine, Bacterial Proteins, Structural Biology, Type III Secretion Systems, Bacteria pathogenesis, Secretion, Protein Interaction Maps, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Molecular Biology, 030304 developmental biology, Adenosine Triphosphatases, 0303 health sciences, Protein-Protein interaction, biology, Mass spectrometry, Chemistry, Effector, Type 3 Secretion System, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Cell biology, Cytoplasm, Chaperone (protein), Pseudomonas aeruginosa, biology.protein, 030217 neurology & neurosurgery, Molecular Chaperones
Abstract

International audience; Pseudomonas aeruginosa is an opportunistic bacterium of which the main virulence factor is the Type III Secretion System. The ATPase of this machinery, PscN (SctN), is thought to be localized at the base of the secretion apparatus and to participate in the recognition, chaperone dissociation and unfolding of exported T3SS proteins. In this work, a protein-protein interaction ELISA revealed the interaction of PscN with a wide range of exported T3SS proteins including the needle, translocator, gate-keeper and effector. These interactions were further confirmed by Microscale Thermophoresis that also indicated a preferential interaction of PscN with secreted proteins or protein-chaperone complex rather than with chaperones alone, in line with the release of the chaperones in the bacterial cytoplasm after the dissociation from their exported proteins. Moreover, we suggest a new role of the gate-keeper complex and the ATPase in the regulation of early substrates recognition by the T3SS. This finding sheds a new light on the mechanism of secretion switching from early to middle substrates in P. aeruginosa .

Published
2020
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8. Inflammasome activation by <scp> Pseudomonas aeruginosa ' </scp> s <scp>ExlA</scp> pore‐forming toxin is detrimental for the host

Author

Benoit Gallet, Vincent Deruelle, Stéphanie Bouillot, Philippe Huber, Ina Attrée, Stéphane Pont, Christine Moriscot, Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), Pathogenèse bactérienne et réponses cellulaires (PBRC), Centre National de la Recherche Scientifique (CNRS)-Biologie du Cancer et de l'Infection (BCI ), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
Lipopolysaccharide, Inflammasomes, Interleukin-1beta, Immunology, Virulence, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Biology, medicine.disease_cause, Microbiology, Mice, 03 medical and health sciences, chemistry.chemical_compound, Leukocidins, Interleukin-1alpha, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Virology, Type III Secretion Systems, medicine, Animals, Pseudomonas Infections, Secretion, Lung, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Inflammation, 0303 health sciences, Pore-forming toxin, 030306 microbiology, Pseudomonas aeruginosa, Toxin, Macrophages, Pyroptosis, Receptors, Interleukin-1, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Inflammasome, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Peptide Fragments, Neutrophil Infiltration, chemistry, Cytokines, medicine.drug
Abstract

During acute Pseudomonas aeruginosa infection, the inflammatory response is essential for bacterial clearance. Neutrophil recruitment can be initiated following the assembly of an inflammasome within sentinel macrophages, leading to activation of caspase-1, which in turn triggers macrophage pyroptosis and IL-1β/IL-18 maturation. Inflammasome formation can be induced by a number of bacterial determinants, including Type III secretion systems (T3SSs) or pore-forming toxins, or, alternatively, by lipopolysaccharide (LPS) via caspase-11 activation. Surprisingly, previous studies indicated that a T3SS-induced inflammasome increased pathogenicity in mouse models of P. aeruginosa infection. Here, we investigated the immune reaction of mice infected with a T3SS-negative P. aeruginosa strain (IHMA879472). Virulence of this strain relies on ExlA, a secreted pore-forming toxin. IHMA879472 promoted massive neutrophil infiltration in infected lungs, owing to efficient priming of toll-like receptors, and thus enhanced the expression of inflammatory proteins including pro-IL-1β and TNF-α. However, mature-IL-1β and IL-18 were undetectable in wild-type mice, suggesting that ExlA failed to effectively activate caspase-1. Nevertheless, caspase-1/11 deficiency improved survival following infection with IHMA879472, as previously described for T3SS+ bacteria. We conclude that the detrimental effect associated with the ExlA-induced inflammasome is probably not due to hyperinflammation, rather it stems from another inflammasome-dependent process.

Published
2020
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9. Species-specific recruitment of transcription factors dictates toxin expression

Author

Trouillon, Julian, Sentausa, Erwin, Ragno, Michel, Robert-Genthon, Mylène, Lory, Stephen, Attrée, Ina, Elsen, Sylvie, Pathogenèse bactérienne et réponses cellulaires (PBRC), Centre National de la Recherche Scientifique (CNRS)-Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Harvard Medical School [Boston] (HMS), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), and ATTREE, Ina

Subjects
Base Sequence, Virulence, Gene regulation, Chromatin and Epigenetics, Bacterial Toxins, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Gene Expression Regulation, Bacterial, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Repressor Proteins, Bacterial Proteins, Species Specificity, A549 Cells, Pseudomonas, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Operon, [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Humans, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Promoter Regions, Genetic, ComputingMilieux_MISCELLANEOUS, Protein Binding, Transcription Factors
Abstract

Tight and coordinate regulation of virulence determinants is essential for bacterial biology and involves dynamic shaping of transcriptional regulatory networks during evolution. The horizontally transferred two-partner secretion system ExlB–ExlA is instrumental in the virulence of different Pseudomonas species, ranging from soil- and plant-dwelling biocontrol agents to the major human pathogen Pseudomonas aeruginosa. Here, we identify a Cro/CI-like repressor, named ErfA, which together with Vfr, a CRP-like activator, controls exlBA expression in P. aeruginosa. The characterization of ErfA regulon across P. aeruginosa subfamilies revealed a second conserved target, the ergAB operon, with functions unrelated to virulence. To gain insights into this functional dichotomy, we defined the pan-regulon of ErfA in several Pseudomonas species and found ergAB as the sole conserved target of ErfA. The analysis of 446 exlBA promoter sequences from all exlBA+ genomes revealed a wide variety of regulatory sequences, as ErfA- and Vfr-binding sites were found to have evolved specifically in P. aeruginosa and nearly each species carries different regulatory sequences for this operon. We propose that the emergence of different regulatory cis-elements in the promoters of horizontally transferred genes is an example of plasticity of regulatory networks evolving to provide an adapted response in each individual niche.

Published
2020
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10. The human NAIP-NLRC4-inflammasome senses the Pseudomonas aeruginosa T3SS inner-rod protein

Author

Marion Thepaut, Laura Monlezun, B. Guery, Eric Faudry, Eric Kipnis, Rodrigue Dessein, Teddy Grandjean, Anne Boucher, Université de Lille, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Centre Hospitalier Universitaire Vaudois [Lausanne] (CHUV)

Subjects
0301 basic medicine, Inflammasomes, THP-1 Cells, Interleukin-1beta, medicine.disease_cause, [SDV.IMM.II]Life Sciences [q-bio]/Immunology/Innate immunity, Type three secretion system, Mice, 0302 clinical medicine, NLRC4, Type III Secretion Systems, Immunology and Allergy, Toll-like receptor, biology, Chemistry, Caspase 1, NOD-like receptor, Inflammasome, General Medicine, Neuronal Apoptosis-Inhibitory Protein, Innate Immunity, Salmonella enterica, Pseudomonas aeruginosa, Intercellular Signaling Peptides and Proteins, medicine.drug, Immunology, Microbiology, 03 medical and health sciences, Pathogen-associated microbial pattern, medicine, Animals, Humans, Pseudomonas Infections, Nod-like receptor, Macrophages, Calcium-Binding Proteins, Pathogen-Associated Molecular Pattern Molecules, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Immunity, Innate, Toll-Like Receptor 2, CARD Signaling Adaptor Proteins, Toll-Like Receptor 4, 030104 developmental biology, bacteria, NAIP, Carrier Proteins, 030215 immunology
Abstract

While NLRC4-dependent sensing of intracellular Gram-negative pathogens such as Salmonella enterica serovar typhimurium is a beneficial host response, NLRC4-dependent sensing of the Pseudomonas aeruginosa type 3 secretion system (T3SS) has been shown to be involved in pathogenicity. In mice, different pathogen-associated microbial patterns are sensed by the combination of the NLRC4-inflammasome with different neuronal apoptosis inhibitory proteins (NAIPs). NAIP2 is involved in sensing PscI, an inner-rod protein of the P. aeruginosa T3SS. Surprisingly, only a single human NAIP (hNAIP) has been found. Moreover, there is no description of hNAIP-NLRC4 inflammasome recognition of T3SS inner-rod proteins in humans. Here, we show that the P. aeruginosa T3SS inner-rod protein PscI and needle protein PscF are both sensed by the hNAIP-NLRC4 inflammasome in human macrophages and PBMCs from healthy donors, allowing caspase-1 and IL-1β maturation and resulting in a robust inflammatory response. TLR4 and TLR2 are involved in redundantly sensing these two T3SS components.

Published
2017
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11. Baseplate Component TssK and Spatio-Temporal Assembly of T6SS in Pseudomonas aeruginosa

Author

David Liebl, Mylène Robert-Genthon, Viviana Job, Valentina Cogoni, Ina Attrée, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)

Subjects
Microbiology (medical), molecular nanomachine, Cell, Phosphatase, lcsh:QR1-502, baseplate assembly, T4 bacteriophage, medicine.disease_cause, Microbiology, lcsh:Microbiology, 03 medical and health sciences, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], medicine, Inner membrane, PPPA, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Type VI secretion system, Original Research, 0303 health sciences, biology, 030306 microbiology, Pseudomonas aeruginosa, Chemistry, Kinase, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Cell biology, medicine.anatomical_structure, T6SS, bacterial competition, Bacteria
Abstract

The Gram-negative bacteria use the contractile multi-molecular structure, called the Type VI Secretion System (T6SS) to inject toxic products into eukaryotic and prokaryotic cells. In this study, we use fluorescent protein fusions and time-lapse microscopy imaging to study the assembly dynamics of the baseplate protein TssK in Pseudomonas aeruginosa T6SS. TssK formed transient higher-order structures that correlated with dynamics of sheath component TssB. Assembly of peri-membrane TssK structures occurred de novo upon contact with competing bacteria. We show that this assembly required presence of TagQ-TagR envelope sensors, activity of PpkA kinase and anchoring to the inner membrane via TssM. Disassembly and repositioning of TssK component was dependent on PppA phosphatase and indispensable for repositioning and deployment of the entire contractile apparatus toward a new target cell. We also show that TssE is necessary for correct elongation and stability of TssB-sheath, but not for TssK assembly. Therefore, in P. aeruginosa, assembly of the TssK-containing structure relays on the post-translational regulatory envelope module and acts as spatio-temporal marker for further recruitment and subsequent assembly of the contractile apparatus.

Published
2019
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12. An unusual community-acquired invasive and multi systemic infection due to ExoU-harboring Pseudomonas aeruginosa strain: Clinical disease and microbiological characteristics

Author

Muriel Fartoukh, Guillaume Voiriot, Michel Djibré, Charlotte Verdet, Stéphane Pont, François Cretin, Alexandre Elabbadi, Patrick Plésiat, CHU Tenon [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon), Service de réanimation médicale et infectieuse, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-AP-HP - Hôpital Bichat - Claude Bernard [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Université Paris Diderot - Paris 7 (UPD7), Service de Réanimation et USC Médico-Chirurgicale [CHU Tenon], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Service des soins intensifs [CHU Tenon], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Tenon [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Service de Réanimation médico-chirurgicale [CHU Tenon], Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Tenon [APHP], Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), Hôpital Jean Minjoz, Centre Hospitalier Régional Universitaire [Besançon] (CHRU Besançon), Université Paris Diderot - Paris 7 (UPD7)-AP-HP - Hôpital Bichat - Claude Bernard [Paris]-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), and Service de réanimation et USC médico-chirurgicale [CHU Tenon]

Subjects
Male, 0301 basic medicine, Microbiology (medical), medicine.medical_treatment, 030106 microbiology, lcsh:QR1-502, Virulence, medicine.disease_cause, lcsh:Microbiology, Microbiology, 03 medical and health sciences, 0302 clinical medicine, Pseudomonas aeruginosa Infections, Bacterial Proteins, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Sepsis, medicine, Humans, Immunology and Allergy, Pseudomonas Infections, 030212 general & internal medicine, Invasive infection, Lung, General Immunology and Microbiology, Strain (chemistry), Pseudomonas aeruginosa, business.industry, Immunosuppression, General Medicine, Middle Aged, Clinical disease, Shock, Septic, Systemic Inflammatory Response Syndrome, 3. Good health, Community-Acquired Infections, Infectious Diseases, medicine.anatomical_structure, A549 Cells, business, Immunocompetence
Abstract

International audience; Community-acquired Pseudomonas aeruginosa infections are rare. Most cases involve patients either with underlying immunosuppression or structural chronic lung diseases. We report here an atypical case of a severe community-acquired invasive infection due to a hypervirulent ExoU-producing strain, in an immunocompetent patient.

Published
2019
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13. Stories from the wall: Envelope-associated functions in bacteria. Focus on cell wall synthesis, protein secretion & signal transduction machineries

Author

Maillard, Antoine P., MAILLARD, Antoine, Groupe Pathogenèse Bactérienne et Réponses Cellulaires / Bacterial Pathogenesis and Cellular Responses Group (IBS-PBRC), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Communauté Université Grenoble Alpes, Christelle Breton, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Structure and function, Paroi bactérienne, Relations structure fonction, Facteurs sigma ECF, SecYEG-DF-YajC, Bacterial cell wall, Signalisation transmembranaire, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Bacterial envelope, Cobalt nickel resistance, Transmembrane signaling, Factor essential for expression of methicillin resistance, Enveloppe bactérienne, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Protein secretion, Exolysin, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Sécrétion protéique, Sigma factors
Published
2019

14. Insertion sequences drive the emergence of a highly adapted human pathogen

Author

Pauline Basso, Ina Attree, Gwendoline Bellement, Sylvie Elsen, Yohann Couté, Annie Adrait, Stephen Lory, Alice Berry, Erwin Sentausa, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Etude de la dynamique des protéomes (EDyP ), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Harvard Medical School [Boston] (HMS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
Proteomics, antibiotic resistance, Virulence Factors, Virulence, Human pathogen, Hemorrhage, adaptation, Moths, medicine.disease_cause, Microbiology, Transcriptome, 03 medical and health sciences, Antibiotic resistance, Bacterial Proteins, medicine, Animals, Humans, Pseudomonas Infections, Insertion sequence, Gene, Phylogeny, 030304 developmental biology, Genetics, 0303 health sciences, biology, Whole Genome Sequencing, 030306 microbiology, Pseudomonas aeruginosa, Gene Expression Profiling, bacterial infection, General Medicine, Gene Expression Regulation, Bacterial, Genomics, Pneumonia, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Microbe-niche Interactions: Host Adaptation, Disease Models, Animal, DNA Transposable Elements, Mobile genetic elements, Bacteria, Genome, Bacterial, multiomics, Research Article
Abstract

Pseudomonas aeruginosa is a highly adaptive opportunistic pathogen that can have serious health consequences in patients with lung disorders. Taxonomic outliers of P. aeruginosa of environmental origin have recently emerged as infectious for humans. Here, we present the first genome-wide analysis of an isolate that caused fatal haemorrhagic pneumonia. In two clones, CLJ1 and CLJ3, sequentially recovered from a patient with chronic pulmonary disease, insertion of a mobile genetic element into the P. aeruginosa chromosome affected major virulence-associated phenotypes and led to increased resistance to the antibiotics used to combat the infection. Comparative genome, proteome and transcriptome analyses revealed that this ISL3-family insertion sequence disrupted the genes for flagellar components, type IV pili, O-specific antigens, translesion polymerase and enzymes producing hydrogen cyanide. Seven-fold more insertions were detected in the later isolate, CLJ3, than in CLJ1, some of which modified strain susceptibility to antibiotics by disrupting the genes for the outer-membrane porin OprD and the regulator of β-lactamase expression AmpD. In the Galleria mellonella larvae model, the two strains displayed different levels of virulence, with CLJ1 being highly pathogenic. This study revealed insertion sequences to be major players in enhancing the pathogenic potential of a P. aeruginosa taxonomic outlier by modulating both its virulence and its resistance to antimicrobials, and explains how this bacterium adapts from the environment to a human host.

Published
2018
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15. cAMP and Vfr Control Exolysin Expression and Cytotoxicity of Pseudomonas aeruginosa Taxonomic Outliers

Author

Kook Han, Julian Trouillon, Stephen Lory, Mylène Robert-Genthon, Michel Ragno, Alice Berry, Ina Attrée, Sylvie Elsen, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Department of Microbiology and Immunology, and Harvard Medical School [Boston] (HMS)

Subjects
0301 basic medicine, Cyclic AMP Receptor Protein, Operon, [SDV]Life Sciences [q-bio], Bacterial Toxins, 030106 microbiology, Mutant, Virulence, TPS, Biology, medicine.disease_cause, Microbiology, Virulence factor, Cell Line, Type three secretion system, exolysin, 03 medical and health sciences, Bacterial Proteins, cAMP, Cyclic AMP, medicine, Humans, Pseudomonas Infections, Secretion, Frameshift Mutation, Promoter Regions, Genetic, Vfr, Molecular Biology, Regulation of gene expression, Base Sequence, Pseudomonas aeruginosa, PA7 group, Gene Expression Regulation, Bacterial, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 3. Good health, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, gene regulation, Research Article, Adenylyl Cyclases
Abstract

The two-partner secretion system ExlBA, expressed by strains of Pseudomonas aeruginosa belonging to the PA7 group, induces hemorrhage in lungs due to disruption of host cellular membranes. Here we demonstrate that the exlBA genes are controlled by a pathway consisting of cAMP and the virulence factor regulator (Vfr). Upon interaction with cAMP, Vfr binds directly to the exlBA promoter with high affinity (equilibrium binding constant [ K eq ] of ≈2.5 nM). The exlB and exlA expression was diminished in the Vfr-negative mutant and upregulated with increased intracellular cAMP levels. The Vfr binding sequence in the exlBA promoter was mutated in situ , resulting in reduced cytotoxicity of the mutant, showing that Vfr is required for the exlBA expression during intoxication of epithelial cells. Vfr also regulates function of type 4 pili previously shown to facilitate ExlA activity on epithelial cells, which indicates that the cAMP/Vfr pathway coordinates these two factors needed for full cytotoxicity. As in most P. aeruginosa strains, the adenylate cyclase CyaB is the main provider of cAMP for Vfr regulation during both in vitro growth and eukaryotic cell infection. We discovered that the absence of functional Vfr in the reference strain PA7 is caused by a frameshift in the gene and accounts for its reduced cytotoxicity, revealing the conservation of ExlBA control by the CyaB-cAMP/Vfr pathway in P. aeruginosa taxonomic outliers. IMPORTANCE The human opportunistic pathogen Pseudomonas aeruginosa provokes severe acute and chronic human infections associated with defined sets of virulence factors. The main virulence determinant of P. aeruginosa taxonomic outliers is exolysin, a membrane-disrupting pore-forming toxin belonging to the two-partner secretion system ExlBA. In this work, we demonstrate that the conserved CyaB-cAMP/Vfr pathway controls cytotoxicity of outlier clinical strains through direct transcriptional activation of the exlBA operon. Therefore, despite the fact that the type III secretion system and exolysin are mutually exclusive in classical and outlier strains, respectively, these two major virulence determinants share similarities in their mechanisms of regulation.

Published
2018
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16. Corrigendum: Pseudomonas aeruginosa Takes a Multi-Target Approach to Achieve Junction Breach

Author

Emeline Reboud, Guillaume Golovkine, Philippe Huber, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Huber, Philippe

Subjects
0301 basic medicine, Microbiology (medical), endothelium, Immunology, lcsh:QR1-502, bacterial virulence factors, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, medicine.disease_cause, Microbiology, Cell junction, lcsh:Microbiology, 03 medical and health sciences, Multi target, bacterial secretion systems, medicine, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, ComputingMilieux_MISCELLANEOUS, Chemistry, Pseudomonas aeruginosa, bacterial invasion, Epithelium, Cell biology, 030104 developmental biology, Infectious Diseases, medicine.anatomical_structure, intercellular junctions, epithelium
Abstract

International audience

Published
2018
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17. Pore-forming activity of the $Pseudomonas\ aeruginosa$ type III secretion system translocon alters the host epigenome

Author

Charlotte Lombardi, Alain Filloux, Laurent Dortet, François Cretin, Andréa Dessen, AP-HP Hôpital Bicêtre (Le Kremlin-Bicêtre), MRC Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom, Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Brazilian Biosciences National Laboratory (LNBio), National Center for Research in Energy and Materials, Vaincre la Mucoviscidose RF20140501133, ANR project PRP1.4 T3SS, European Project: 654909,H2020,H2020-MSCA-IF-2014,T6SS-PSEUDO-LIP(2016), Université Grenoble Alpes, Inserm, CEA, BIG-Biologie du Cancer et de l’Infection, Grenoble, France, Imperial College London, Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Medical Research Council (MRC)

Subjects
0301 basic medicine, EFFECTOR TARGETS, NF-KAPPA-B, Moths, medicine.disease_cause, Applied Microbiology and Biotechnology, Virulence factor, Epigenesis, Genetic, Type three secretion system, Histones, INFECTION, Type III Secretion Systems, MESH: Animals, MESH: Epigenesis, Genetic, PHOSPHORYLATION, MESH: Bacterial Proteins, Host cell membrane, MESH: Histones, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Effector, Chemistry, MESH: Moths, EPITHELIAL-CELLS, Translocon, Cell biology, Histone Code, Larva, Host-Pathogen Interactions, Pseudomonas aeruginosa, MESH: Pseudomonas aeruginosa, Life Sciences & Biomedicine, Microbiology (medical), GENES, Immunology, Microbiology, 03 medical and health sciences, MESH: Type III Secretion Systems, Bacterial Proteins, Genetics, medicine, Animals, Humans, Secretion, HISTONE H3, PROTEIN PHOSPHATASES, Antigens, Bacterial, Science & Technology, MESH: Humans, Cell Membrane, MESH: Host-Pathogen Interactions, Cell Biology, Epigenome, biochemical phenomena, metabolism, and nutrition, MAPK, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 030104 developmental biology, MESH: Histone Code, A549 Cells, MESH: HeLa Cells, bacteria, MESH: A549 Cells, VI SECRETION, MESH: Larva, MESH: Antigens, Bacterial, HeLa Cells, MESH: Cell Membrane
Abstract

Recent studies highlight that bacterial pathogens can reprogram target cells by influencing epigenetic factors. The type III secretion system (T3SS) is a bacterial nanomachine that resembles a syringe on the bacterial surface. The T3SS ‘needle’ delivers translocon proteins into eukaryotic cell membranes, subsequently allowing injection of bacterial effectors into the cytosol. Here we show that Pseudomonas aeruginosa induces early T3SS-dependent dephosphorylation and deacetylation of histone H3 in eukaryotic cells. This is not triggered by any of the P. aeruginosa T3SS effectors, but results from the insertion of the PopB–PopD translocon into the membrane. This suggests that the P. aeruginosa translocon is a genuine T3SS effector acting as a pore-forming toxin. We visualized the translocon plugged into the host cell membrane after the bacterium has left the site of contact, and demonstrate that subsequent ion exchange through this pore is responsible for histone H3 modifications and host cell subversion. The pore-forming activity of the Pseudomonas aeruginosa type III secretion system translocon serves as a virulence factor to induce host epigenome modification and promote infection.

Published
2018
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18. Pseudomonas aeruginosa Takes a Multi-Target Approach to Achieve Junction Breach

Author

Emeline Reboud, Philippe Huber, Guillaume Golovkine, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Huber, Philippe

Subjects
0301 basic medicine, Microbiology (medical), endothelium, Endothelium, Mini Review, Immunology, lcsh:QR1-502, Virulence, bacterial virulence factors, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Biology, medicine.disease_cause, Microbiology, Cell junction, lcsh:Microbiology, 03 medical and health sciences, Opportunistic pathogen, Multi target, bacterial secretion systems, medicine, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, ComputingMilieux_MISCELLANEOUS, Pseudomonas aeruginosa, Correction, bacterial invasion, Epithelium, 030104 developmental biology, Infectious Diseases, medicine.anatomical_structure, intercellular junctions, epithelium
Abstract

Pseudomonas aeruginosa is an opportunistic pathogen which uses a number of strategies to cross epithelial and endothelial barriers at cell–cell junctions. In this review, we describe how the coordinated actions of P. aeruginosa's virulence factors trigger various molecular mechanisms to disarm the junctional gate responsible for tissue integrity.

Published
2018
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19. CLIQ-BID: A method to quantify bacteria-induced damage to eukaryotic cells by automated live-imaging of bright nuclei

Author

Stéphanie Bouillot, Ina Attree, Emmanuelle Soleilhac, Yann Wallez, Philippe Huber, Eric Faudry, Pathogénie bactérienne et réponses cellulaires, Centre National de la Recherche Scientifique (CNRS) - Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Biologie du Cancer et de l'Infection (BCI - UMR S1036), Commissariat à l'énergie atomique et aux énergies alternatives (CEA) - Institut National de la Santé et de la Recherche Médicale (INSERM) - Université Grenoble Alpes (UGA), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Commissariat à l'énergie atomique et aux énergies alternatives (CEA) - Université Grenoble Alpes [Saint Martin d'Hères] - Institut National de la Santé et de la Recherche Médicale (INSERM), Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Genetics and Chemogenomics (GenChem), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), AVIESAN T3SS (ANR PRP1.4), IBiSA, ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), ANR-15-CE11-0018,HemoPseudo,Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence(2015), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Faudry, Eric, Grenoble Alliance for Integrated Structural Cell Biology - - GRAL2010 - ANR-10-LABX-0049 - LABX - VALID, and Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence - - HemoPseudo2015 - ANR-15-CE11-0018 - AAPG2015 - VALID

Subjects
0301 basic medicine, Programmed cell death, 030106 microbiology, Cell, lcsh:Medicine, Virulence, [SDV.BC.IC] Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], Bacterial growth, Bacterial Physiological Phenomena, medicine.disease_cause, Article, Mice, 03 medical and health sciences, Live cell imaging, [SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], Human Umbilical Vein Endothelial Cells, medicine, Animals, Humans, lcsh:Science, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, Multidisciplinary, biology, 030306 microbiology, lcsh:R, Endothelial Cells, Pathogenic bacteria, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Molecular Imaging, 3. Good health, Cell biology, Eukaryotic Cells, 030104 developmental biology, medicine.anatomical_structure, NIH 3T3 Cells, lcsh:Q, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Ex vivo, Bacteria, HeLa Cells
Abstract

Pathogenic bacteria induce eukaryotic cell damage which range from discrete modifications of signalling pathways, to morphological alterations and even to cell death. Accurate quantitative detection of these events is necessary for studying host-pathogen interactions and for developing strategies to protect host organisms from bacterial infections. Investigation of morphological changes is cumbersome and not adapted to high-throughput and kinetics measurements. Here, we describe a simple and cost-effective method based on automated analysis of live cells with stained nuclei, which allows real-time quantification of bacteria-induced eukaryotic cell damage at single-cell resolution. We demonstrate that this automated high-throughput microscopy approach permits screening of libraries composed of interference-RNA, bacterial strains, antibodies and chemical compounds in ex vivo infection settings. The use of fluorescently-labelled bacteria enables the concomitant detection of changes in bacterial growth. Using this method named CLIQ-BID (Cell Live Imaging Quantification of Bacteria Induced Damage), we were able to distinguish the virulence profiles of different pathogenic bacterial species and clinical strains.

Published
2018
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20. Exolysin Shapes the Virulence of Pseudomonas aeruginosa Clonal Outliers

Author

Emeline Reboud, Pauline Basso, Antoine P. Maillard, Philippe Huber, Ina Attrée, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Huber, Philippe

Subjects
Pore Forming Cytotoxic Proteins, two-partner secretion, ExlA, Virulence, type IV pili, Protein Conformation, lcsh:R, Bacterial Toxins, lcsh:Medicine, ADAM10, Review, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, inflammation, Pseudomonas aeruginosa, pore-forming toxin, PA7-like strains, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, cell junctions, ComputingMilieux_MISCELLANEOUS
Abstract

Bacterial toxins are important weapons of toxicogenic pathogens. Depending on their origin, structure and targets, they show diverse mechanisms of action and effects on eukaryotic cells. Exolysin is a secreted 170 kDa pore-forming toxin employed by clonal outliers of Pseudomonas aeruginosa providing to some strains a hyper-virulent behaviour. This group of strains lacks the major virulence factor used by classical strains, the Type III secretion system. Here, we review the structural features of the toxin, the mechanism of its secretion and the effects of the pore formation on eukaryotic cells.

Published
2017
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21. IFN-γ extends the immune functions of Guanylate Binding Proteins to inflammasome-independent antibacterial activities during Francisella novicida infection

Author

Sacha Benaoudia, Sophia Djebali, Pierre Wallet, Angelina Provost, Pauline Basso, Igor Golovliov, Anders Sjöstedt, Etienne Meunier, Eric Faudry, Bénédicte F. Py, Fanny Michal, Omran Allatif, Brice Lagrange, Helena Lindgren, Amandine Mosnier, Amandine Martin, Petr Broz, Thomas Henry, Masahiro Yamamoto, Inflammasome, Infections bactériennes et autoinflammation, Inflammasome, Bacterial Infections and Autoinflammation (I2BA), Centre International de Recherche en Infectiologie - UMR (CIRI), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Immunologie de l'allergie cutanée et vaccination – Immunology of skin allergy and vaccination, Laboratory for Molecular Infection Medicine Sweden and Department of Clinical Microbiology, Pathogénie bactérienne et réponses cellulaires, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Immunité et lymphocytes cytotoxiques – Immunity and cytotoxic lymphocytes, Focal Area Infection Biology, Biozentrum, University of Basel (Unibas), Research Institute for Microbial Diseases [Osaka, Japan] (RIMD), Osaka University [Osaka], Inflammasome NLRP3 – NLRP3 Inflammasome, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre International de Recherche en Infectiologie (CIRI), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
0301 basic medicine, Male, Inflammasomes, Fluorescent Antibody Technique, Apoptosis, medicine.disease_cause, Pathology and Laboratory Medicine, Inbred C57BL, Biochemistry, White Blood Cells, Mice, 0302 clinical medicine, Animal Cells, Medicine and Health Sciences, Biology (General), Francisella, Francisella tularensis, Tularemia, Mice, Knockout, Immune System Proteins, Cell Death, Effector, Antimicrobials, Biochemistry and Molecular Biology, Drugs, Inflammasome, Flow Cytometry, 3. Good health, Cell biology, Bacterial Pathogens, Chemistry, Intracellular Pathogens, Cell Processes, Medical Microbiology, Gene Knockdown Techniques, Physical Sciences, [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology, [SDV.IMM]Life Sciences [q-bio]/Immunology, Female, Cellular Types, Pathogens, medicine.drug, Research Article, QH301-705.5, Immune Cells, Knockout, Immunology, Immunoblotting, Enzyme-Linked Immunosorbent Assay, Biology, Microbiology, 03 medical and health sciences, AIM2, Interferon-gamma, Immune system, GTP-Binding Proteins, Virology, Microbial Control, Genetics, medicine, Animals, Francisella novicida, Molecular Biology, Microbial Pathogens, Pharmacology, Blood Cells, Bacteria, Animal, Intracellular parasite, Macrophages, Chemical Compounds, Organisms, Biology and Life Sciences, Proteins, Cell Biology, RC581-607, Iodides, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Mice, Inbred C57BL, Disease Models, Animal, 030104 developmental biology, Disease Models, Antibacterials, Parasitology, Immunologic diseases. Allergy, Gram-Negative Bacterial Infections, Inflammasome complex, Biokemi och molekylärbiologi, 030215 immunology
Abstract

Guanylate binding proteins (GBPs) are interferon-inducible proteins involved in the cell-intrinsic immunity against numerous intracellular pathogens. The molecular mechanisms underlying the potent antibacterial activity of GBPs are still unclear. GBPs have been functionally linked to the NLRP3, the AIM2 and the caspase-11 inflammasomes. Two opposing models are currently proposed to explain the GBPs-inflammasome link: i) GBPs would target intracellular bacteria or bacteria-containing vacuoles to increase cytosolic PAMPs release ii) GBPs would directly facilitate inflammasome complex assembly. Using Francisella novicida infection, we investigated the functional interactions between GBPs and the inflammasome. GBPs, induced in a type I IFN-dependent manner, are required for the F. novicida-mediated AIM2-inflammasome pathway. Here, we demonstrate that GBPs action is not restricted to the AIM2 inflammasome, but controls in a hierarchical manner the activation of different inflammasomes complexes and apoptotic caspases. IFN-γ induces a quantitative switch in GBPs levels and redirects pyroptotic and apoptotic pathways under the control of GBPs. Furthermore, upon IFN-γ priming, F. novicida-infected macrophages restrict cytosolic bacterial replication in a GBP-dependent and inflammasome-independent manner. Finally, in a mouse model of tularemia, we demonstrate that the inflammasome and the GBPs are two key immune pathways functioning largely independently to control F. novicida infection. Altogether, our results indicate that GBPs are the master effectors of IFN-γ-mediated responses against F. novicida to control antibacterial immune responses in inflammasome-dependent and independent manners., Author summary The cell-intrinsic immunity is defined as the mechanisms allowing a host cell infected by an intracellular pathogen to mount effective immune mechanisms to detect and eliminate pathogens without any help from other immune cells. In infected macrophages, the Guanylate Binding Proteins (GBPs) are immune proteins, induced at low levels in a cell autonomous manner by endogenous type I IFN or at high levels following IFN-γ production by innate and adaptive lymphocytes. The antibacterial activity of GBPs has been recently tightly linked to the inflammasomes. Inflammasomes are innate immune complexes leading to inflammatory caspases activation and death of the infected cell. Francisella novicida, a bacterium replicating in the macrophage cytosol, is closely related to F. tularensis, the agent of tularemia and is used as a model to study cytosolic immunity. GBPs contribute to F. novicida lysis within the host cytosol leading to DNA release and AIM2 inflammasome activation. In addition to their regulation of the AIM2 inflammasome, we identified that GBPs also control several other pyroptotic and apoptotic pathways activated in a hierarchical manner. Furthermore, we demonstrate that IFN-γ priming extends GBPs anti-microbial responses from the inflammasome-dependent control of cell death to an inflammasome-independent control of cytosolic bacterial replication. Our results, validated in a mouse model of tularemia, thus segregate the antimicrobial activities of inflammasomes and GBPs as well as highlight GBPs as the master effectors of IFN-γ-mediated cytosolic immunity.

Published
2017
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22. Pseudomonas aeruginosa ExlA and Serratia marcescens ShlA trigger cadherin cleavage by promoting calcium influx and ADAM10 activation

Author

Ina Attrée, Philippe Huber, Stéphanie Bouillot, Benoît Béganton, Emeline Reboud, Sabine Patot, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Pathogénie des Staphylocoques – Staphylococcal Pathogenesis (StaPath), Centre International de Recherche en Infectiologie - UMR (CIRI), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), ANR-15-CE11-0018,HemoPseudo,Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence(2015), Centre International de Recherche en Infectiologie (CIRI), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
0301 basic medicine, Serratia, Cell, Cell Membranes, Toxicology, Pathology and Laboratory Medicine, Cell junction, Epithelium, Mice, Hemolysin Proteins, ADAM10 Protein, Animal Cells, [SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], Medicine and Health Sciences, Toxins, lcsh:QH301-705.5, Inbred BALB C, Serratia marcescens, Mice, Inbred BALB C, Microscopy, Microscopy, Confocal, medicine.diagnostic_test, Virulence, Blotting, Cadherins, Transmembrane protein, Cell biology, Bacterial Pathogens, medicine.anatomical_structure, Medical Microbiology, Confocal, Pseudomonas aeruginosa, [SDV.IMM]Life Sciences [q-bio]/Immunology, Female, Cellular Structures and Organelles, Pathogens, Cellular Types, Anatomy, Western, Research Article, lcsh:Immunologic diseases. Allergy, Virulence Factors, Proteolysis, Immunology, Toxic Agents, Blotting, Western, Bacterial Toxins, Biology, Microbiology, 03 medical and health sciences, Enzyme activator, Enterobacteriaceae, Bacterial Proteins, Pseudomonas, Virology, Genetics, medicine, Cell Adhesion, Humans, Animals, Secretion, Molecular Biology, Microbial Pathogens, Bacteria, Cadherin, Host Cells, Organisms, Biology and Life Sciences, Endothelial Cells, Epithelial Cells, Cell Biology, Intracellular Membranes, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Enzyme Activation, Cytosol, 030104 developmental biology, Biological Tissue, lcsh:Biology (General), Parasitology, Calcium, lcsh:RC581-607, Gram-Negative Bacterial Infections, Viral Transmission and Infection
Abstract

Pore-forming toxins are potent virulence factors secreted by a large array of bacteria. Here, we deciphered the action of ExlA from Pseudomonas aeruginosa and ShlA from Serratia marcescens on host cell-cell junctions. ExlA and ShlA are two members of a unique family of pore-forming toxins secreted by a two-component secretion system. Bacteria secreting either toxin induced an ExlA- or ShlA-dependent rapid cleavage of E-cadherin and VE-cadherin in epithelial and endothelial cells, respectively. Cadherin proteolysis was executed by ADAM10, a host cell transmembrane metalloprotease. ADAM10 activation is controlled in the host cell by cytosolic Ca2+ concentration. We show that Ca2+ influx, induced by ExlA or ShlA pore formation in the plasma membrane, triggered ADAM10 activation, thereby leading to cadherin cleavage. Our data suggest that ADAM10 is not a cellular receptor for ExlA and ShlA, further confirming that ADAM10 activation occurred via Ca2+ signalling. In conclusion, ExlA- and ShlA-secreting bacteria subvert a regulation mechanism of ADAM10 to activate cadherin shedding, inducing intercellular junction rupture, cell rounding and loss of tissue barrier integrity., Author summary Pore-forming toxins are the most widespread toxins delivered by pathogenic bacteria and are required for full virulence. Pore-forming toxins perforate membranes of host cells for intracellular delivery of bacterial factors, for bacterial escape from phagosomes or in order to kill cells. Loss of membrane integrity, especially the plasma membrane, has broad implications on cell and tissue physiology. Here, we show that two members of a unique family of pore-forming toxins, secreted by Pseudomonas aeruginosa and Serratia marcescens, have the capacity to disrupt cell-cell junctions of epithelial and endothelial cells, hence breaching two major tissue barriers.

Published
2017
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23. Pseudomonas aeruginosa Exolysin promotes bacterial growth in lungs, alveolar damage and bacterial dissemination

Author

François Cretin, Guillaume Golovkine, Emmanuel Lemichez, Philippe Huber, Benoit Gallet, Stéphanie Bouillot, Patrick Munro, Ina Attree, Guy Schoehn, Emeline Reboud, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre méditerranéen de médecine moléculaire (C3M), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), This work was supported by institutional grants from the Commissariat à l’Energie Atomique, the Institut National de la Santé Et de la Recherche Médicale, the Université Grenoble-Alpes and the Centre National de la Recherche Scientifique, as well as the Laboratoire d’Excellence GRAL [grant number ANR-10-LABX-49-01 to ER] and SIGNALIFE [grant number ANR-11-LABX-28-01], Agence National de la Recherche [ANR-15-CE11-0018-01]. This work used the platforms of the Grenoble Instruct centre (ISBG, UMS 3518 CNRS-CEA-UJF-EMBL) with support from FRISBI (ANR-10-INSB-05-02) and GRAL (ANR-10-LABX-49-01) within the Grenoble Partnership for Structural Biology (PSB). The electron microscope facility is supported by the Rhône-Alpes Region, the Fondation Recherche Medicale (FRM), the fonds FEDER, the Centre National de la Recherche Scientifique (CNRS), the Commissariat à l’Energie Atomique, the University of Grenoble, EMBL, and the GIS-Infrastrutures en Biologie Sante et Agronomie (IBISA)., Grenoble Instruct-ERIC Center (ISBG : UMS 3518 CNRS-CEA-UGA-EMBL), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), ANR-11-LABX-0028,SIGNALIFE,Réseau d'Innovation sur les Voies de Signalisation en Sciences de la Vie(2011), ANR-15-CE11-0018,HemoPseudo,Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence(2015), ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), Université Grenoble Alpes, Inserm, CEA, BIG-Biologie du Cancer et de l’Infection, Grenoble, France, Huber, Philippe, Grenoble Alliance for Integrated Structural Cell Biology - - GRAL2010 - ANR-10-LABX-0049 - LABX - VALID, Centres d'excellences - Réseau d'Innovation sur les Voies de Signalisation en Sciences de la Vie - - SIGNALIFE2011 - ANR-11-LABX-0028 - LABX - VALID, Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence - - HemoPseudo2015 - ANR-15-CE11-0018 - AAPG2015 - VALID, Infrastructure Française pour la Biologie Structurale Intégrée - - FRISBI2010 - ANR-10-INBS-0005 - INBS - VALID, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Côte d'Azur (UCA), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
0301 basic medicine, Pore Forming Cytotoxic Proteins, Science, medicine.medical_treatment, Phagocytosis, Bacterial Toxins, MESH: Mice, Inbred BALB C, Bacteremia, Biology, medicine.disease_cause, MESH: Alveolar Epithelial Cells, Virulence factor, Article, Microbiology, Type three secretion system, 03 medical and health sciences, Mice, Immune system, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, medicine, Animals, MESH: Animals, MESH: Bacteremia, MESH: Phagocytosis, MESH: Mice, Mice, Inbred BALB C, Multidisciplinary, Lung, MESH: Pore Forming Cytotoxic Proteins, Pseudomonas aeruginosa, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 3. Good health, 030104 developmental biology, Cytokine, medicine.anatomical_structure, MESH: Bacterial Toxins, Alveolar Epithelial Cells, MESH: Pseudomonas aeruginosa, [SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Medicine, Ectopic expression, Female, MESH: Female
Abstract

Exolysin (ExlA) is a recently-identified pore-forming toxin secreted by a subset of Pseudomonas aeruginosa strains identified worldwide and devoid of Type III secretion system (T3SS), a major virulence factor. Here, we characterized at the ultrastructural level the lesions caused by an ExlA-secreting strain, CLJ1, in mouse infected lungs. CLJ1 induced necrotic lesions in pneumocytes and endothelial cells, resulting in alveolo-vascular barrier breakdown. Ectopic expression of ExlA in an exlA-negative strain induced similar tissue injuries. In addition, ExlA conferred on bacteria the capacity to proliferate in lungs and to disseminate in secondary organs, similar to bacteria possessing a functional T3SS. CLJ1 did not promote a strong neutrophil infiltration in the alveoli, owing to the weak pro-inflammatory cytokine reaction engendered by the strain. However, CLJ1 was rapidly eliminated from the blood in a bacteremia model, suggesting that it can be promptly phagocytosed by immune cells. Together, our study ascribes to ExlA-secreting bacteria the capacity to proliferate in the lung and to damage pulmonary tissues, thereby promoting metastatic infections, in absence of substantial immune response exacerbation.

Published
2017
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24. Multiple Pseudomonas species secrete exolysin-like toxins and provoke Caspase-1-dependent macrophage death

Author

Basso, Pauline, Wallet, Pierre, Elsen, Sylvie, Soleilhac, Emmanuelle, Henry, Thomas, Faudry, Eric, Attrée, Ina, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Inflammasome, Infections bactériennes et autoinflammation, Inflammasome, Bacterial Infections and Autoinflammation (I2BA), Centre International de Recherche en Infectiologie (CIRI), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Genetics and Chemogenomics (GenChem), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre International de Recherche en Infectiologie - UMR (CIRI), Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Cell Death, Inflammasomes, Macrophages, Bacterial Toxins, Caspase 1, Interleukin-1beta, Apoptosis, Bone Marrow Cells, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Mice, Inbred C57BL, Mice, Bacterial Proteins, Pseudomonas, [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology, [SDV.IMM]Life Sciences [q-bio]/Immunology, Animals
Abstract

International audience; Pathogenic bacteria secrete protein toxins that provoke apoptosis or necrosis of eukaryotic cells. Here, we developed a live-imaging method, based on incorporation of a DNA-intercalating dye into membrane-damaged host cells, to study the kinetics of primary bone marrow-derived macrophages (BMDMs) mortality induced by opportunistic pathogen Pseudomonas aeruginosa expressing either Type III Secretion System (T3SS) toxins or the pore-forming toxin, Exolysin (ExlA). We found that ExlA promotes the activation of Caspase-1 and maturation of interleukin-1β. BMDMs deficient for Caspase-1 and Caspase-11 were resistant to ExlA-induced death. Furthermore, by using KO BMDMs, we determined that the upstream NLRP3/ASC complex leads to the Caspase-1 activation. We also demonstrated that Pseudomonas putida and Pseudomonas protegens and the Drosophila pathogen Pseudomonas entomophila, which naturally express ExlA-like toxins, are cytotoxic toward macrophages and provoke the same type of pro-inflammatory death as does ExlA+ P. aeruginosa. These results demonstrate that ExlA-like toxins of two-partner secretion systems from diverse Pseudomonas species activate the NLRP3 inflammasome and provoke inflammatory pyroptotic death of macrophages.

Published
2017
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25. Defining Lipoprotein Localisation by Fluorescence Microscopy

Author

Didier Grunwald, Mylène Robert-Genthon, Ina Attrée, Maria Guillermina Casabona, Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Pathogenèse bactérienne et réponses cellulaires (PBRC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0301 basic medicine, Chemistry, fungi, 030106 microbiology, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, Fusion protein, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Green fluorescent protein, Transport protein, Cell biology, 03 medical and health sciences, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Fluorescence microscope, Secretion, Cell envelope, Bacterial outer membrane, mCherry, ComputingMilieux_MISCELLANEOUS
Abstract

In recent years it has become evident that lipoproteins play crucial roles in the assembly of bacterial envelope-embedded nanomachineries and in the processes of protein export/secretion. In this chapter we describe a method to determine their precise localisation, for example inner versus outer membrane, in Gram-negative bacteria using human opportunistic pathogen Pseudomonas aeruginosa as a model. A fusion protein between a given putative lipoprotein and the red fluorescent protein mCherry must be created and expressed in a strain expressing cytoplasmic green fluorescent protein (GFP). Then the peripheral localisation of the fusion protein in the cell can be examined by treating cells with lysozyme to create spheroplasts and monitoring fluorescence under a confocal microscope. Mutants in the signal peptide can be engineered to study the association with the membrane and efficiency of transport. This protocol can be adapted to monitor lipoprotein localisation in other Gram-negative bacteria.

Published
2017
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26. Pseudomonas aeruginosa Pore-Forming Exolysin and Type IV Pili Cooperate To Induce Host Cell Lysis

Author

Pauline Basso, Michel Ragno, Sylvie Elsen, Emeline Reboud, Guillaume Golovkine, Stephanie Bouillot, Philippe Huber, Stephen Lory, Eric Faudry, Ina Attrée, Samuel I. Miller, Huber, Philippe, Grenoble Alliance for Integrated Structural Cell Biology - - GRAL2010 - ANR-10-LABX-0049 - LABX - VALID, Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence - - HemoPseudo2015 - ANR-15-CE11-0018 - AAPG2015 - VALID, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Harvard Medical School [Boston] (HMS), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), and ANR-15-CE11-0018,HemoPseudo,Pneumonie hémorragique à Pseudomonas aeruginosa : étude de nouvelles stratégies de virulence(2015)

Subjects
0301 basic medicine, Pore Forming Cytotoxic Proteins, Cell Survival, 030106 microbiology, Virulence, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Biology, Microbiology, Type three secretion system, Cell membrane, 03 medical and health sciences, Virology, Type II Secretion Systems, medicine, Secretion, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, Host cell membrane, Effector, QR1-502, Cytolysis, Mutagenesis, Insertional, medicine.anatomical_structure, Fimbriae, Bacterial, Pseudomonas aeruginosa, DNA Transposable Elements, Bacterial outer membrane, Research Article
Abstract

Clinical strains of Pseudomonas aeruginosa lacking the type III secretion system genes employ a toxin, exolysin (ExlA), for host cell membrane disruption. Here, we demonstrated that ExlA export requires a predicted outer membrane protein, ExlB, showing that ExlA and ExlB define a new active two-partner secretion (TPS) system of P. aeruginosa. In addition to the TPS signals, ExlA harbors several distinct domains, which include one hemagglutinin domain, five arginine-glycine-aspartic acid (RGD) motifs, and a C-terminal region lacking any identifiable sequence motifs. However, this C-terminal region is important for the toxic activity, since its deletion abolishes host cell lysis. Using lipid vesicles and eukaryotic cells, including red blood cells, we demonstrated that ExlA has a pore-forming activity which precedes cell membrane disruption of nucleated cells. Finally, we developed a high-throughput cell-based live-dead assay and used it to screen a transposon mutant library of an ExlA-producing P. aeruginosa clinical strain for bacterial factors required for ExlA-mediated toxicity. The screen resulted in the identification of proteins involved in the formation of type IV pili as being required for ExlA to exert its cytotoxic activity by promoting close contact between bacteria and the host cell. These findings represent the first example of cooperation between a pore-forming toxin of the TPS family and surface appendages in host cell intoxication., IMPORTANCE The course and outcome of acute, toxigenic infections by Pseudomonas aeruginosa clinical isolates rely on the deployment of one of two virulence strategies: delivery of effectors by the well-known type III secretion system or the cytolytic activity of the recently identified two-partner secreted toxin, exolysin. Here, we characterize several features of the mammalian cell intoxication process mediated by exolysin. We found that exolysin requires the outer membrane protein ExlB for export into extracellular medium. Using in vitro recombinant protein and ex vivo assays, we demonstrated a pore-forming activity of exolysin. A cellular cytotoxicity screen of a transposon mutant library, made in an exolysin-producing clinical strain, identified type IV pili as bacterial appendages required for exolysin toxic function. This work deciphers molecular mechanisms underlying the activity of novel virulence factors used by P. aeruginosa clinical strains lacking the type III secretion system, including a requirement for the toxin-producing bacteria to be attached to the targeted cell to induce cytolysis, and defines new targets for developing antivirulence strategies.

Published
2017
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27. Host cell surfaces induce a Type IV pili-dependent alteration of bacterial swimming

Author

Laurence Lemelle, Claire Burny, Philippe Huber, Guillaume Golovkine, Cédric Vaillant, Jean-François Palierne, Christophe Place, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Sciences de la Terre (LST), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Laboratoire Joliot Curie, École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Huber, Philippe, and École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL)

Subjects
0301 basic medicine, 030106 microbiology, Fimbria, Microbial metabolism, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, medicine.disease_cause, Article, Virulence factor, Pilus, 03 medical and health sciences, Human Umbilical Vein Endothelial Cells, medicine, Humans, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, ComputingMilieux_MISCELLANEOUS, Multidisciplinary, biology, Pseudomonas aeruginosa, Pathogenic bacteria, biology.organism_classification, Cell biology, On cells, 030104 developmental biology, Fimbriae, Bacterial, Host-Pathogen Interactions, human activities, Bacteria
Abstract

For most pathogenic bacteria, flagellar motility is recognized as a virulence factor. Here, we analysed the swimming behaviour of bacteria close to eukaryotic cellular surfaces, using the major opportunistic pathogen Pseudomonas aeruginosa as a model. We delineated three classes of swimming trajectories on both cellular surfaces and glass that could be differentiated by their speeds and local curvatures, resulting from different levels of hydrodynamic interactions with the surface. Segmentation of the trajectories into linear and curved sections or pause allowed us to precisely describe the corresponding swimming patterns near the two surfaces. We concluded that (i) the trajectory classes were of same nature on cells and glass, however the trajectory distribution was strikingly different between surface types, (ii) on cell monolayers, a larger fraction of bacteria adopted a swimming mode with stronger bacteria-surface interaction mostly dependent upon Type IV pili. Thus, bacteria swim near boundaries with diverse patterns and importantly, Type IV pili differentially influence swimming near cellular and abiotic surfaces.

Published
2016
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28. Phenotype and toxicity of the recently discovered exlA -positive Pseudomonas aeruginosa strains collected worldwide

Author

Emeline, Reboud, Sylvie, Elsen, Stéphanie, Bouillot, Guillaume, Golovkine, Pauline, Basso, Katy, Jeannot, Ina, Attrée, Philippe, Huber, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre National de Référence de la Résistance aux Antibiotiques (CNR), Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon), and Service de bactériologie [Besançon]

Subjects
Mice, Inbred BALB C, Virulence, Virulence Factors, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Chicory, Mice, Phenotype, Bacterial Proteins, Pseudomonas aeruginosa, Animals, Humans, Female, Pseudomonas Infections, Phylogeny
Abstract

International audience; We recently identified a hypervirulent strain of Pseudomonas aeruginosa, differing significantly from the classical strains in that it lacks the type 3 secretion system (T3SS), a major determinant of P. aeruginosa virulence. This new strain secretes a novel toxin, called ExlA, which induces plasma membrane rupture in host cells. For this study, we collected 18 other exlA-positive T3SS-negative strains, analyzed their main virulence factors and tested their toxicity in various models. Phylogenetic analysis revealed two groups. The strains were isolated on five continents from patients with various pathologies or in the environment. Their proteolytic activity and their motion abilities were highly different, as well as their capacity to infect epithelial, endothelial, fibroblastic and immune cells, which correlated directly with ExlA secretion levels. In contrast, their toxicity towards human erythrocytes was limited. Some strains were hypervirulent in a mouse pneumonia model and others on chicory leaves. We conclude that (i) exlA-positive strains can colonize different habitats and may induce various infection types, (ii) the strains secreting significant amounts of ExlA are cytotoxic for most cell types but are poorly hemolytic, (iii) toxicity in planta does not correlate with ExlA secretion.

Published
2016
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29. Pseudomonas aeruginosa renews its virulence factors

Author

Huber, Philippe, Basso, Pauline, Reboud, Emeline, Attree, Ina, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
[SDV.BC]Life Sciences [q-bio]/Cellular Biology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016
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30. Structural Basis of Lipid Targeting and Destruction by the Type V Secretion System of Pseudomonas aeruginosa

Author

Pauline Basso, Sophie Bleves, Carlos Contreras-Martel, Eric Faudry, David Neves, Andréa Dessen, Aurélie Laubier, Richard Salacha, Paulo Vinicius da Mata Madeira, Samira Zouhir, Brazilian National Laboratory for Biosciences (LNBio), Centro Nacional de Pesquisa em Energia e materiais, Centra Nacional de Pesquisa-Centra Nacional de Pesquisa, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'ingénierie des systèmes macromoléculaires (LISM), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU), Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Laboratoire International Associé BACWALL, Association Vaincre la Mucoviscidose - RF20120600685 et RF20130500911, FAPESP - 11/52067-6, 2014/11980-9 et 2013/01962-0, ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Models, Molecular, 0301 basic medicine, Protein Conformation, Type V Secretion Systems, 030106 microbiology, Virulence, Phospholipase, Biology, Crystallography, X-Ray, Phosphatidylinositols, Substrate Specificity, 03 medical and health sciences, Bacterial Proteins, Phospholipase A1, Structural Biology, Catalytic Domain, Hydrolase, Secretion, Lipase, Molecular Biology, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Active site, Transport protein, 030104 developmental biology, Biochemistry, Phospholipases, Pseudomonas aeruginosa, biology.protein
Abstract

International audience; The type V secretion system is a macromolecular machine employed by a number of bacteria to secrete virulence factors into the environment. The human pathogen Pseudomonas aeruginosa employs the newly described type Vd secretion system to secrete a soluble variant of PlpD, a lipase of the patatin-like family synthesized as a single macromolecule that also carries a polypeptide transport-associated domain and a 16-stranded β-barrel. Here we report the crystal structure of the secreted form of PlpD in its biologically active state. PlpD displays a classical lipase α/β hydrolase fold with a catalytic site located within a highly hydrophobic channel that entraps a lipidic molecule. The active site is covered by a flexible lid, as in other lipases, indicating that this region in PlpD must modify its conformation in order for catalysis at the water-lipid interface to occur. PlpD displays phospholipase A1 activity and is able to recognize a number of phosphatidylinositols and other phosphatidyl analogs. PlpD is the first example of an active phospholipase secreted through the type V secretion system, for which there are more than 200 homologs, revealing details of the lipid destruction arsenal expressed by P. aeruginosa in order to establish infection.

Published
2016
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31. Functional Consequences of Calcium Influx Promoted by Bacterial Pore-Forming Toxins

Author

Philippe Huber, Stéphanie Bouillot, Emeline Reboud, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Huber, Philippe

Subjects
Pore Forming Cytotoxic Proteins, 0301 basic medicine, Cell signaling, Cell type, Programmed cell death, ion flux, Health, Toxicology and Mutagenesis, Host–pathogen interaction, Bacterial Toxins, lcsh:Medicine, Review, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Toxicology, 03 medical and health sciences, 0302 clinical medicine, Animals, Humans, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, ComputingMilieux_MISCELLANEOUS, Pore-forming toxin, Chemistry, lcsh:R, Cell biology, bacterial virulence factor, Cytosol, Intercellular Junctions, cell death, 030104 developmental biology, Calcium, Efflux, Signal transduction, host–pathogen interaction, signal transduction, 030217 neurology & neurosurgery
Abstract

Bacterial pore-forming toxins induce a rapid and massive increase in cytosolic Ca2+ concentration due to the formation of pores in the plasma membrane and/or activation of Ca2+-channels. As Ca2+ is an essential messenger in cellular signaling, a sustained increase in Ca2+ concentration has dramatic consequences on cellular behavior, eventually leading to cell death. However, host cells have adapted mechanisms to protect against Ca2+ intoxication, such as Ca2+ efflux and membrane repair. The final outcome depends upon the nature and concentration of the toxin and on the cell type. This review highlights the repercussions of Ca2+ overload on the induction of cell death, repair mechanisms, cellular adhesive properties, and the inflammatory response.

Published
2018
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32. Pseudomonas aeruginosa Transmigrates at Epithelial Cell-Cell Junctions, Exploiting Sites of Cell Division and Senescent Cell Extrusion

Author

Guillaume Golovkine, Eric Faudry, Philippe Huber, Sylvie Elsen, Stéphanie Bouillot, Ina Attree, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), CEA Nanobio, ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), Huber, Philippe, and Grenoble Alliance for Integrated Structural Cell Biology - - GRAL2010 - ANR-10-LABX-0049 - LABX - VALID

Subjects
0301 basic medicine, Cell division, QH301-705.5, Immunology, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Flagellum, Biology, Transfection, medicine.disease_cause, Microbiology, Cell junction, Cell Line, Madin Darby Canine Kidney Cells, Type three secretion system, 03 medical and health sciences, Dogs, Virology, Genetics, medicine, Animals, Humans, Pseudomonas Infections, Biology (General), Cytoskeleton, Molecular Biology, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, Cellular Senescence, Microscopy, Confocal, 030102 biochemistry & molecular biology, Pseudomonas aeruginosa, Epithelial Cells, RC581-607, Immunohistochemistry, Epithelium, Cell biology, Intercellular Junctions, 030104 developmental biology, medicine.anatomical_structure, Parasitology, Immunologic diseases. Allergy, Cell aging, Cell Division, Research Article
Abstract

To achieve systemic infection, bacterial pathogens must overcome the critical and challenging step of transmigration across epithelial barriers. This is particularly true for opportunistic pathogens such as Pseudomonas aeruginosa, an agent which causes nosocomial infections. Despite extensive study, details on the mechanisms used by this bacterium to transmigrate across epithelial tissues, as well as the entry sites it uses, remain speculative. Here, using real-time microscopy and a model epithelial barrier, we show that P. aeruginosa employs a paracellular transmigration route, taking advantage of altered cell-cell junctions at sites of cell division or when senescent cells are expelled from the cell layer. Once a bacterium transmigrates, it is followed by a cohort of bacteria using the same entry point. The basal compartment is then invaded radially from the initial penetration site. Effective transmigration and propagation require type 4 pili, the type 3 secretion system (T3SS) and a flagellum, although flagellum-deficient bacteria can occasionally invade the basal compartment from wounded areas. In the basal compartment, the bacteria inject the T3SS toxins into host cells, disrupting the cytoskeleton and focal contacts to allow their progression under the cells. Thus, P. aeruginosa exploits intrinsic host cell processes to breach the epithelium and invade the subcellular compartment., Author Summary In normal situations, the mucosae constitute efficient barriers against the invasion of opportunistic pathogens. The bacteria inducing nosocomial infections take advantage of pre-existing pathological situations to cross the epithelium and spread in deeper tissues. The conditions on the host side permitting transmigration and the combination of virulence factors used by the bacteria to transmigrate are mostly speculative. Here, we studied the transmigration process of Pseudomonas aeruginosa, a bacterium causing hospital-acquired acute and chronic infections. We found that bacteria exploits weakened cell-cell junctions of the epithelium, such as those generated at sites of cell division or when dying cells are extruded from the cell layer, to breach the cell layer, using specific virulence factors and motility appendages.

Published
2016
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33. Idiosyncratic features in tRNAs participating in bacterial cell wall synthesis

Author

Nathalie Josseaume, Lionel Dubost, Claudine Mayer, Jean-Marc Valery, Jean-Emmanuel Hugonnet, Stéphane Mesnage, Mélanie Etheve-Quelquejeu, Maryline Chemama, Michel Arthur, Antoine P. Maillard, Matthieu Fonvielle, Patricia Busca, Arul Marie, Régis Villet, Structure bactérienne et résistance aux antibiotiques (CRC - Inserm U1138), Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques (LCBPT - UMR 8601), Université Paris Descartes - Paris 5 (UPD5)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche des Cordeliers (CRC), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire de chimie et biochimie des substances naturelles, Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Molécules de Communication et Adaptation des Micro-Organismes (MCAM), Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire de Recherche Moléculaire sur les Antibiotiques, Université Pierre et Marie Curie - Paris 6 (UPMC)-IFR58-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Krebs Inst, University of Sheffield [Sheffield], Université Paris Diderot - Paris 7 (UPD7), Synthèse, Structure et Fonction de Molécules Bioactives (SSFMB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-École Pratique des Hautes Études (EPHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE), Muséum national d'Histoire naturelle (MNHN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), École pratique des hautes études (EPHE)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-École pratique des hautes études (EPHE)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Université Paris Descartes - Paris 5 (UPD5)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire de Chimie et Biochimie des Substances Naturelles, Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Models, Molecular, Base pair, [SDV]Life Sciences [q-bio], Molecular Sequence Data, RNA, Transfer, Ala, Peptidoglycan, Wobble base pair, MESH: Base Sequence, Biology, 03 medical and health sciences, chemistry.chemical_compound, MESH: Cell Wall, Cell Wall, Genetics, Transferase, Nucleotide, Peptide Synthases, MESH: RNA, Transfer, Ala, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, MESH: Molecular Sequence Data, Bacteria, Base Sequence, Nucleic Acid Enzymes, MESH: Peptidoglycan, 030306 microbiology, Mutagenesis, MESH: Peptide Synthases, Amino acid, MESH: Bacteria, MESH: Mutagenesis, Site-Directed, chemistry, Biochemistry, Transfer RNA, Mutagenesis, Site-Directed, MESH: Uridine Diphosphate N-Acetylmuramic Acid, MESH: Models, Molecular
Abstract

International audience; The FemX(Wv) aminoacyl transferase of Weissella viridescens initiates the synthesis of the side chain of peptidoglycan precursors by transferring l-Ala from Ala-tRNA(Ala) to UDP-MurNAc-pentadepsipeptide. FemX(Wv) is an attractive target for the development of novel antibiotics, since the side chain is essential for the last cross-linking step of peptidoglycan synthesis. Here, we show that FemX(Wv) is highly specific for incorporation of l-Ala in vivo based on extensive analysis of the structure of peptidoglycan. Comparison of various natural and in vitro-transcribed tRNAs indicated that the specificity of FemX(Wv) depends mainly upon the sequence of the tRNA although additional specificity determinants may include post-transcriptional modifications and recognition of the esterified amino acid. Site-directed mutagenesis identified cytosines in the G1-C72 and G2-C71 base pairs of the acceptor stem as critical for FemX(Wv) activity in agreement with modeling of tRNA(Ala) in the catalytic cavity of the enzyme. In contrast, semi-synthesis of Ala-tRNA(Ala) harboring nucleotide substitutions in the G3-U70 wobble base pair showed that this main identity determinant of alanyl-tRNA synthetase is non-essential for FemX(Wv). The different modes of recognition of the acceptor stem indicate that specific inhibition of FemX(Wv) could be achieved by targeting the distal portion of tRNA(Ala) for the design of substrate analogues.

Published
2007
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34. ExsB Is Required for Correct Assembly of the Pseudomonas aeruginosa Type III Secretion Apparatus in the Bacterial Membrane and Full Virulence In Vivo

Author

Ariel J. Blocker, Stéphanie Bouillot, Caroline Perdu, Eric Faudry, Philippe Huber, Sylvie Elsen, Ina Attree, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), University of Bristol [Bristol], IRTELIS Ph.D. program from CEA, and Faudry, Eric

Subjects
Male, Operon, Virulence Factors, Lipoproteins, Immunology, Virulence, Biology, medicine.disease_cause, Microbiology, Bacterial Proteins, medicine, Animals, Humans, Secretion, Pseudomonas Infections, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Bacterial Secretion Systems, [SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Cells, Cultured, Regulator gene, Mice, Inbred BALB C, Pseudomonas aeruginosa, Endothelial Cells, Membrane Proteins, Molecular Pathogenesis, Survival Analysis, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 3. Good health, Cell biology, Disease Models, Animal, Infectious Diseases, Membrane protein, Host cell cytoplasm, bacteria, Parasitology, Protein Multimerization, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Bacterial outer membrane
Abstract

Pseudomonas aeruginosa is responsible for high-morbidity infections of cystic fibrosis patients and is a major agent of nosocomial infections. One of its most potent virulence factors is a type III secretion system (T3SS) that injects toxins directly into the host cell cytoplasm. ExsB, a lipoprotein localized in the bacterial outer membrane, is one of the components of this machinery, of which the function remained elusive until now. The localization of the exsB gene within the exsCEBA regulatory gene operon suggested an implication in the T3SS regulation, while its similarity with yscW from Yersinia spp. argued in favor of a role in machinery assembly. The present work shows that ExsB is necessary for full in vivo virulence of P. aeruginosa . Furthermore, the requirement of ExsB for optimal T3SS assembly and activity is demonstrated using eukaryotic cell infection and in vitro assays. In particular, ExsB promotes the assembly of the T3SS secretin in the bacterial outer membrane, highlighting the molecular role of ExsB as a pilotin. This involvement in the regulation of the T3S apparatus assembly may explain the localization of the ExsB-encoding gene within the regulatory gene operon.

Published
2015
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35. Pharmacological Activation of Rap1 Antagonizes the Endothelial Barrier Disruption Induced by Exotoxins ExoS and ExoT of Pseudomonas aeruginosa

Author

Ina Attrée, Stéphanie Bouillot, Philippe Huber, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Huber, Philippe

Subjects
medicine.medical_treatment, Bacterial Toxins, Telomere-Binding Proteins, Immunology, Enzyme Activators, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Biology, medicine.disease_cause, Microbiology, Shelterin Complex, Type three secretion system, chemistry.chemical_compound, medicine, Humans, Protein kinase A, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, Cells, Cultured, ComputingMilieux_MISCELLANEOUS, ADP Ribose Transferases, Cellular Microbiology: Pathogen-Host Cell Molecular Interactions, Forskolin, Activator (genetics), Effector, Pseudomonas aeruginosa, Colforsin, GTPase-Activating Proteins, Endothelial Cells, 3. Good health, Infectious Diseases, Cytokine, chemistry, Parasitology, Rap1
Abstract

Most clinical strains of Pseudomonas aeruginosa , a leading agent of nosocomial infections, are multiresistant to antibiotherapy. Because of the paucity of new available antibiotics, the investigation of strategies aimed at limiting the action of its major virulence factors has gained much interest. The type 3 secretion system of P. aeruginosa and its effectors are known to be major determinants of toxicity and are required for bacterial dissemination in the host. Bacterial transmigration across the vascular wall is considered to be an important step in the infectious process. Using human endothelial primary cells, we demonstrate that forskolin (FSK), a drug inducing cyclic AMP (cAMP) elevation in eukaryotic cells, strikingly reduced the cell retraction provoked by two type 3 toxins, ExoS and ExoT, found in the majority of clinical strains. Conversely, cytotoxicity of a strain carrying the type 3 effector ExoU was unaffected by FSK. In addition, FSK altered the capacity of two ExoS/ExoT strains to transmigrate across cell monolayers. In agreement with these findings, other drugs and a cytokine inducing the increase of cAMP intracellular levels have also protected cells from retraction. cAMP is an activator of both protein kinase A and EPAC, a GTPase exchange factor of Rap1. Using activators or inhibitors of either pathway, we show that the beneficial effect of FSK is exerted by the activation of the EPAC/Rap1 axis, suggesting that its protective effect is mediated by reinforcing cell-cell and cell-substrate adhesion.

Published
2015
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36. PscI is a type III secretion needle anchoring protein with in vitro polymerization capacities

Author

Laura, Monlezun, David, Liebl, Daphna, Fenel, Teddy, Grandjean, Alice, Berry, Guy, Schoehn, Rodrigue, Dessein, Eric, Faudry, Ina, Attree, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie structurale (IBS - UMR 5075 ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Faculté de Médecine Henri Warembourg - Université de Lille, AVIESAN-CEA, Région Rhône-Alpes, Fondation pour la Recherche Médicale (FRM), EMBL, GIS‐Infrastructures en Biologie Santé et Agronomie (IBISA), Plateforme Microscopie Electronique, ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Université Lille 2 - Faculté de Médecine, Laboratoire de cristallographie et RMN biologiques ( LCRB - UMR 8015 ), Université Paris Descartes - Paris 5 ( UPD5 ) -Centre National de la Recherche Scientifique ( CNRS ), Biologie du Cancer et de l'Infection ( BCI - UMR S1036 ), Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Université Grenoble Alpes ( UGA ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Institut de biologie structurale ( IBS - UMR 5075 ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Joseph Fourier - Grenoble 1 ( UJF ), Université de Lille, Faculté de Médecine, CHRU, Université de Lille, Unité de Nutrition Humaine ( UNH ), Institut National de la Recherche Agronomique ( INRA ) -Université d'Auvergne - Clermont-Ferrand I ( UdA ) -Clermont Université, ANR-10-INSB-05-02,FRISBI,FRISBI, ANR-10- LABX-49-01,Labex GRAL,Labex GRAL, and ANR-08-BLAN-0271,ESCRTbudding,ESCRT-III assembly and budding ( 2008 )

Subjects
Mice, Protein Transport, Bacterial Proteins, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Macrophages, Interleukin-1beta, Pseudomonas aeruginosa, Type III Secretion Systems, Animals, Humans, Pseudomonas Infections, Polymerization, [ SDV.BBM.BS ] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM]
Abstract

International audience; The export of bacterial toxins across the bacterial envelope requires the assembly of complex, membrane-embedded protein architectures. Pseudomonas aeruginosa employs type III secretion (T3S) injectisome to translocate exotoxins directly into the cytoplasm of a target eukaryotic cell. This multi-protein channel crosses two bacterial membranes and extends further as a needle through which the proteins travel. We show in this work that PscI, proposed to form the T3S system (T3SS) inner rod, possesses intrinsic properties to polymerize into flexible and regularly twisted fibrils and activates IL-1β production in mouse bone marrow macrophages in vitro. We also found that point mutations within C-terminal amphipathic helix of PscI alter needle assembly in vitro and T3SS function in cell infection assays, suggesting that this region is essential for an efficient needle assembly. The overexpression of PscF partially compensates for the absence of the inner rod in PscI-deficient mutant by forming a secretion-proficient injectisome. All together, we propose that the polymerized PscI in P. aeruginosa optimizes the injectisome function by anchoring the needle within the envelope-embedded complex of the T3S secretome and - contrary to its counterpart in Salmonella - is not involved in substrate switching.

Published
2015

37. Structure-Based Site-Directed Mutagenesis of the UDP-MurNAc-Pentapeptide-Binding Cavity of the FemX Alanyl Transferase from Weissella viridescens

Author

Wladimir Sougakoff, Sabrina Biarrotte-Sorin, Claudine Mayer, Michel Arthur, Stéphane Mesnage, Antoine P. Maillard, Régis Villet, Ahmed Bouhss, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Krebs Inst, University of Sheffield [Sheffield], Institut de biochimie et biophysique moléculaire et cellulaire (IBBMC), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre d'Immunologie et de Maladies Infectieuses (CIMI), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7), Centre de Recherche des Cordeliers (CRC), Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
Peptidyl transferase, Nitrogenous Group Transferases, [SDV]Life Sciences [q-bio], MESH: Catalytic Domain, Peptide, MESH: Nitrogenous Group Transferases, Biology, Microbiology, MESH: Protein Structure, Tertiary, 03 medical and health sciences, chemistry.chemical_compound, Catalytic Domain, Transferase, Binding site, Site-directed mutagenesis, Molecular Biology, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Binding Sites, Crystallography, MESH: Kinetics, 030306 microbiology, MESH: Crystallography, Mutagenesis, Enzymes and Proteins, MESH: Amino Acid Substitution, Uridine Diphosphate N-Acetylmuramic Acid, Protein Structure, Tertiary, Amino acid, carbohydrates (lipids), Kinetics, Lactobacillus, MESH: Mutagenesis, Site-Directed, Amino Acid Substitution, MESH: Binding Sites, chemistry, Biochemistry, Mutagenesis, Site-Directed, MESH: Uridine Diphosphate N-Acetylmuramic Acid, biology.protein, Peptidoglycan, MESH: Lactobacillus
Abstract

Weissella viridescens FemX (FemX Wv ) belongs to the Fem family of nonribosomal peptidyl transferases that use aminoacyl-tRNA as the amino acid donor to synthesize the peptide cross-bridge found in the peptidoglycan of many species of pathogenic gram-positive bacteria. We have recently solved the crystal structure of FemX Wv in complex with the peptidoglycan precursor UDP-MurNAc-pentapeptide and report here the site-directed mutagenesis of nine residues located in the binding cavity for this substrate. Two substitutions, Lys36Met and Arg211Met, depressed FemX Wv transferase activity below detectable levels without affecting protein folding. Analogues of UDP-MurNAc-pentapeptide lacking the phosphate groups or the C-terminal d -alanyl residues were not substrates of the enzyme. These results indicate that Lys36 and Arg211 participate in a complex hydrogen bond network that connects the C-terminal d -Ala residues to the phosphate groups of UDP-MurNAc-pentapeptide and constrains the substrate in a conformation that is essential for transferase activity.

Published
2005
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38. Hereditary angioedema: Key role for kallikrein and bradykinin in vascular endothelial-cadherin cleavage and edema formation

Author

Mélanie Arboleas, Mariela Subileau, Tiphaine Mannic, Isabelle Vilgrain, Christian Drouet, C. Massot, Philippe Huber, Laurence Bouillet, Clinique de médecine interne, Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble, Physiopathologie vasculaire : interactions cellulaires, signalisation et vieillissement, Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Grenoble Alpes - UFR Pharmacie (UGA UFRP), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Famille BMP dans l'angiogenèse et la lymphangiogenèse (BAL ), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département de Médecine Interne, CHU Grenoble, Groupe de Recherche et d’Étude du Processus Inflammatoire (GREPI), AGeing and IMagery (AGIM), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Pathogenèse bactérienne et réponses cellulaires (PBRC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de développement et vieillissement de l'endothélium, GREPI, Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications, Grenoble - UMR 5525 (TIMC-IMAG), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)

Subjects
Adult, medicine.medical_specialty, Blotting, Western, Immunology, Bradykinin, Neuropeptide, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Peptide hormone, Cleavage (embryo), Capillary Permeability, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Antigens, CD, Internal medicine, Edema, Humans, Immunology and Allergy, Medicine, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, business.industry, Angioedemas, Hereditary, Kallikrein, Middle Aged, Cadherins, medicine.disease, 3. Good health, Endocrinology, medicine.anatomical_structure, 030228 respiratory system, chemistry, Hereditary angioedema, Circulatory system, Female, Kallikreins, business, Biomarkers, Blood vessel
Abstract

International audience

Published
2011
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39. Sequential inactivation of Rho GTPases and Lim kinase by Pseudomonas aeruginosa toxins ExoS and ExoT leads to endothelial monolayer breakdown

Author

Stéphanie Bouillot, Ina Attrée, Sylvie Elsen, Philippe Huber, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Male, rho GTP-Binding Proteins, Stress fiber, Membrane ruffling, Moesin, Bacterial Toxins, macromolecular substances, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Biology, Lim kinase, 03 medical and health sciences, Cellular and Molecular Neuroscience, Mice, Human Umbilical Vein Endothelial Cells, Animals, Humans, Pseudomonas Infections, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Pharmacology, ADP Ribose Transferases, 0303 health sciences, Focal Adhesions, Mice, Inbred BALB C, 030302 biochemistry & molecular biology, GTPase-Activating Proteins, Endothelial Cells, Lim Kinases, Cell Biology, Actin filament severing, Cofilin, Actin cytoskeleton, 3. Good health, Cell biology, Enzyme Activation, Actin Cytoskeleton, Host-Pathogen Interactions, Pseudomonas aeruginosa, Molecular Medicine, Filopodia
Abstract

Pseudomonas aeruginosa is a major human opportunistic pathogen and one of the most important causal agents of bacteremia. For non-blood-borne infection, bacterial dissemination requires the crossing of the vascular endothelium, the main barrier between blood and the surrounding tissues. Here, we investigated the effects of P. aeruginosa type 3 secretion effectors, namely ExoS, ExoT, and ExoY, on regulators of actin cytoskeleton dynamics in primary endothelial cells. ExoS and ExoT similarly affected the Lim kinase-cofilin pathway, thereby promoting actin filament severing. Cofilin activation was also observed in a mouse model of P. aeruginosa-induced acute pneumonia. Rho, Rac, and Cdc42 GTPases were sequentially inactivated, leading to inhibition of membrane ruffling, filopodia, and stress fiber collapse, and focal adhesion disruption. At the end of the process, ExoS and ExoT produced a dramatic retraction in all primary endothelial cell types tested and thus a rupture of the endothelial monolayer. ExoY alone had no effect in this context. Cell retraction could be counteracted by overexpression of actin cytoskeleton regulators. In addition, our data suggest that moesin is neither a direct exotoxin target nor an important player in this process. We conclude that any action leading to inhibition of actin filament breakdown will improve the barrier function of the endothelium during P. aeruginosa infection.

Published
2014
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40. VE-cadherin cleavage by LasB protease from Pseudomonas aeruginosa facilitates type III secretion system toxicity in endothelial cells

Author

Stéphanie Bouillot, Guillaume Golovkine, Ina Attree, Romé Voulhoux, Eric Faudry, Philippe Huber, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'ingénierie des systèmes macromoléculaires (LISM), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), This work was supported by grants from the Commissariat à l’Energie Atomique, the Institut National de la Santé et de la Recherche Médicale, the Centre National de la Recherche Scientifique and Joseph Fourier University. Part of this work was also supported by the Alliance pour les sciences de la VIE et de la SANté program in infectiology and FINOVI foundation., Marinari, Isabelle, and Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU)

Subjects
Male, medicine.medical_treatment, Endothelial cells, Fluorescent Antibody Technique, Pathogenesis, [SDV.BC.IC] Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], Mouse models, Type three secretion system, Mice, Molecular Cell Biology, [SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], Biology (General), Bacterial Secretion Systems, Cells, Cultured, Mice, Inbred BALB C, Tight junction, Metalloendopeptidases, Animal Models, Proteases, Cell disruption, Cadherins, Bacterial Pathogens, Cell biology, Host-Pathogen Interaction, medicine.anatomical_structure, Pseudomonas aeruginosa, Research Article, Endothelium, QH301-705.5, Blotting, Western, Immunology, Biology, Microbiology, Model Organisms, Secretion systems, Bacterial Proteins, Antigens, CD, Virology, Cell Adhesion, Genetics, medicine, Extracellular, Animals, Humans, Pseudomonas Infections, Secretion, Molecular Biology, Tight junctions, Protease, RC581-607, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Actins, Disease Models, Animal, Parasitology, Endothelium, Vascular, Immunologic diseases. Allergy, VE-cadherin, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Abstract

Infection of the vascular system by Pseudomonas aeruginosa (Pa) occurs during bacterial dissemination in the body or in blood-borne infections. Type 3 secretion system (T3SS) toxins from Pa induce a massive retraction when injected into endothelial cells. Here, we addressed the role of type 2 secretion system (T2SS) effectors in this process. Mutants with an inactive T2SS were much less effective than wild-type strains at inducing cell retraction. Furthermore, secretomes from wild-typeswere sufficient to trigger cell-cell junction opening when applied to cells, while T2SS-inactivated mutants had minimal activity. Intoxication was associated with decreased levels of vascular endothelial (VE)-cadherin, a homophilic adhesive protein located at endothelial cell-cell junctions. During the process, the protein was cleaved in the middle of its extracellular domain (positions 335 and 349). VE-cadherin attrition was T3SS-independent but T2SS-dependent. Interestingly, the epithelial (E)-cadherin was unaffected by T2SS effectors, indicating that this mechanism is specific to endothelial cells. We showed that one of the T2SS effectors, the protease LasB, directly affected VE-cadherin proteolysis, hence promoting cell-cell junction disruption. Furthermore, mouse infection with Pa to induce acute pneumonia lead to significant decreases in lung VE-cadherin levels, whereas the decrease was minimal with T2SS-inactivated or LasB-deleted mutant strains. We conclude that the T2SS plays a pivotal role during Pa infection of the vascular system by breaching the endothelial barrier, and propose a model in which the T2SS and the T3SS cooperate to intoxicate endothelial cells., Author Summary Pseudomonas aeruginosa (Pa) is a leading agent of nosocomial infections in humans, and clinical isolates are often multiresistant to antibiotics. As with most Gram-negative bacteria, Pa possesses a type III secretion system which consists of an injectisome through which the bacterium injects exotoxins inducing cytoskeleton collapse and apoptosis. Pa also delivers various toxins in the extracellular milieu by the type II secretion system, including the protease LasB. In order to disseminate throughout the body from the infection site and eventually reach the blood, the bacterium generally needs to cross the main barriers of the organism: the epithelium, the basal lamina and the vascular endothelium. Here we show that LasB specifically cleaves one main component of endothelial cell-to-cell junctions, the adhesive protein VE-cadherin, thus leading to junction disruption and endothelial barrier breakdown. VE-cadherin proteolysis also facilitates the action of type III exotoxins in endothelial cells. This cleavage mechanism is likely of major importance in Pa pathogenesis, as suggested by our bacterial dissemination experiments in mice.

Published
2014
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41. Pore Formation by T3SS Translocators: Liposome Leakage Assay

Author

Caroline Perdu, Eric Faudry, Ina Attree, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0303 health sciences, Liposome, biology, 030302 biochemistry & molecular biology, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Transport protein, Type three secretion system, [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, 03 medical and health sciences, chemistry.chemical_compound, Membrane, Dextran, chemistry, Cytoplasm, Chaperone (protein), biology.protein, Biophysics, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Guanidine, 030304 developmental biology
Abstract

International audience; Gram-negative bacteria utilize a dedicated membrane-embedded apparatus, the type III secretion system (T3SS), to inject proteins into host cells. The passage of the proteins across the target membrane is accomplished by a proteinaceous pore-the translocon-formed within the host-cell cytoplasmic membrane. Translocators bound to their chaperones can be expressed in Escherichia coli and subsequently dissociated from the chaperone by guanidine treatment. The pore formation properties of the translocators can then be studied by an in-vitro liposome leakage assay. Sulforhodamine-B is encapsulated within lipid vesicles during liposome preparation. At high concentration, this fluorochrome exhibits self-quenching limiting fluorescence emission. Upon pore formation, liposome leakage leads to the dilution of Sulforhodamine-B in the medium and fluorescence emission increases. Alternatively, fluorochromes coupled to large dextran molecules can be encapsulated in order to estimate pore dimensions. Here we describe protein expression and purification, dye-liposome preparation, and leakage assay conditions.

Published
2013
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42. Current Fluctuation Analysis of the PopB and PopD Translocon Components of the Pseudomonas aeruginosa Type III Secretion System

Author

Ina Attree, Anne H. Delcour, Eric Faudry, Beau Wager, Tyler Wills, University of Houston, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Faudry, Eric

Subjects
Lipid Bilayers, Biophysics, [SDV.BBM.BP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, Biology, Protein Refolding, Type three secretion system, 03 medical and health sciences, Mice, Bacterial Proteins, Animals, Secretion, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Lipid bilayer, [SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Guanidine, 030304 developmental biology, Host cell membrane, 0303 health sciences, Antigens, Bacterial, 030306 microbiology, Macrophages, Osmolar Concentration, Membrane, Conductance, Membranes, Artificial, Hydrogen-Ion Concentration, Translocon, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 3. Good health, Electrophysiological Phenomena, [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, Biochemistry, Ionic strength, Pseudomonas aeruginosa, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Porosity
Abstract

International audience; Pseudomonas aeruginosa is a major agent of hospital-acquired infections, and a pathogen of immunocompromised, cystic fibrosis and burn patients. It uses a type III secretion system for the injection of toxins directly into host cells, through a translocon assembled in the host cell membrane. The hydrophobic translocator subunits of this system, PopB and PopD, have membrane permeabilizing activity based on previous dye leakage experiments, but little is known about the mechanism of assembly and the pore properties of this translocon. Using electrophysiology, we have observed that an equimolar mixture of PopB and PopD induces current fluctuations in planar lipid bilayers, with a unitary conductance of 57 pS in 1 M KCl and numerous larger conductance levels. The activity depends on voltage magnitude and polarity, and increases with protein concentration and the duration of the voltage step. PopB alone is sufficient for producing current fluctuations. PopD rarely displays any transitions, but accelerates PopB onset of activity. The effects of pH, ionic strength, and lipid composition have also been explored. Our data provide new, to our knowledge, insights into the behavior of PopB and PopD by highlighting similarities with secreted pore-forming peptides, and by suggesting that PopB/PopD may form channels via the toroidal pore model. We believe that the events we report here represent the initial steps of insertion and assembly of these translocators in the membrane.

Published
2013
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43. Stoichiometry of the MexA-OprM binding, as investigated by blue native gel electrophoresis

Author

Arnaud Ducruix, Martin Picard, Yann Ferrandez, Houssain Benabdelhak, Pierre Falson, Philippe Benas, Gilles Phan, Nathalie Ulryck, Isabelle Broutin, Laura Monlezun, Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de cristallographie et RMN biologiques (LCRB - UMR 8015), Université Paris Descartes - Paris 5 (UPD5)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Architecture et Réactivité de l'ARN (ARN), Institut de biologie moléculaire et cellulaire (IBMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de biochimie et biophysique moléculaire et cellulaire (IBBMC), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Microbiologie moléculaire et biochimie structurale / Molecular Microbiology and Structural Biochemistry (MMSB), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'enzymologie et biochimie structurales (LEBS), Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA), and broutin, isabelle

Subjects
[SDV]Life Sciences [q-bio], Clinical Biochemistry, Trimer, Palmitic Acids, medicine.disease_cause, Biochemistry, Analytical Chemistry, 03 medical and health sciences, medicine, Escherichia coli, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, biology, Pseudomonas aeruginosa, 030302 biochemistry & molecular biology, Membrane Transport Proteins, Native Polyacrylamide Gel Electrophoresis, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Drug Resistance, Multiple, 3. Good health, Multiple drug resistance, [SDV] Life Sciences [q-bio], Multiprotein Complexes, Electrophoresis, Polyacrylamide Gel, Efflux, Bacteria, Stoichiometry, Bacterial Outer Membrane Proteins, Protein Binding
Abstract

Multidrug resistance has become a serious concern in the treatment of bacterial infections. A prominent role is ascribed to the active efflux of xenobiotics out of the bacteria by a tripartite protein machinery. The mechanism of drug extrusion is rather well understood, thanks to the X-ray structures obtained for the Escherichia coli TolC/AcrA/AcrB model system and the related Pseudomonas aeruginosa OprM/MexA/MexB. However, many questions remain unresolved, in particular the stoichiometry of the efflux pump assembly. On the basis of blue native polyacrylamide gel electrophoresis (BN-PAGE) (Wittig et al., Nat. Protoc. 2006, 1, 418-428), we analyzed the binding stoichiometry of both palmitylated and non-palmitylated MexA with the cognate partner OprM trimer at different ratios and detergent conditions. We found that β-octyl glucopyranoside (β-OG) detergent was not suitable for this technique. Then we proved that MexA has to be palmitylated in order to stabilized the complex formation with OprM. Finally, we provided evidence for a two by two (2, 4, 6, or upper) binding of palmitylated MexA per trimer of OprM.

Published
2012
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44. Biostructural analysis of the metal-sensor domain of CnrX from Cupriavidus metallidurans CH34

Author

Guillaume Pompidor, Stéphanie Ramella-Pairin, Richard Kahn, Antoine P. Maillard, Beate Bersch, Eric Girard, Jacques Covès, Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)

Subjects
MESH: Signal Transduction, MESH: Sequence Analysis, DNA, Magnetic Resonance Spectroscopy, Dimer, [SDV]Life Sciences [q-bio], MESH: Amino Acid Sequence, chemistry.chemical_compound, MESH: Structure-Activity Relationship, X-Ray Diffraction, Cloning, Molecular, Peptide sequence, Protein secondary structure, MESH: Bacterial Proteins, MESH: Crystallization, 0303 health sciences, MESH: Gene Expression Regulation, Bacterial, Cupriavidus, MESH: Periplasm, MESH: X-Ray Diffraction, General Medicine, Nuclear magnetic resonance spectroscopy, MESH: Metals, Heavy, Biochemistry, visual_art, Periplasm, visual_art.visual_art_medium, Crystallization, Dimerization, Signal Transduction, Molecular Sequence Data, Size-exclusion chromatography, Biology, Microbiology, Metal, Structure-Activity Relationship, 03 medical and health sciences, Bacterial Proteins, Metals, Heavy, Drug Resistance, Bacterial, MESH: Drug Resistance, Bacterial, MESH: Cloning, Molecular, Amino Acid Sequence, Molecular Biology, 030304 developmental biology, MESH: Cupriavidus, MESH: Molecular Sequence Data, 030306 microbiology, Cupriavidus metallidurans, MESH: Magnetic Resonance Spectroscopy, Gene Expression Regulation, Bacterial, Sequence Analysis, DNA, Periplasmic space, biology.organism_classification, Crystallography, chemistry, MESH: Dimerization
Abstract

International audience; In Cupriavidus metallidurans CH34, the proteins CnrX, CnrY, and CnrH regulate the expression of the cnrCBA operon that codes for a cation-efflux pump involved in cobalt and nickel resistance. The periplasmic part of CnrX can be defined as the metal sensor in the signal transduction complex composed of the membrane-bound anti-sigma factor CnrY and the extra-cytoplasmic function sigma factor CnrH. A soluble form of CnrX was overproduced and purified. This protein behaves as a dimer in solution as judged from gel filtration, sedimentation velocity experiments, and NMR. Native crystals diffracting to 2.3 A using synchrotron radiation were obtained using the hanging-drop vapor-diffusion method. They belong to the primitive monoclinic space group P2(1), with unit cell parameters a = 31.87, b = 74.80, c = 93.67 A, beta = 90.107 degrees. NMR data and secondary structure prediction suggest that this protein is essentially formed by helices.

Published
2009
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45. X-ray structure of the metal-sensor CnrX in both the apo- and copper-bound forms

Author

Jacques Covès, Serge Gambarelli, Eric Girard, Antoine P. Maillard, Guillaume Pompidor, Richard Kahn, Institut de biologie structurale (IBS - UMR 5075 ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Service de Chimie Inorganique et Biologique (SCIB - UMR E3), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Metal-sensor, Protein Conformation, [SDV]Life Sciences [q-bio], MESH: Amino Acid Sequence, Signal transduction, Crystallography, X-Ray, 01 natural sciences, Biochemistry, chemistry.chemical_compound, MESH: Apoproteins, MESH: Protein Structure, Tertiary, Protein structure, MESH: Protein Conformation, Structural Biology, Cupriavidus metallidurans CH34, MESH: Bacterial Proteins, 0303 health sciences, biology, Resolution (electron density), Cupriavidus, 3. Good health, MESH: Copper, visual_art, visual_art.visual_art_medium, Periplasmic Proteins, Dimerization, Stereochemistry, Molecular Sequence Data, Biophysics, chemistry.chemical_element, CnrX, 010402 general chemistry, Metal, 03 medical and health sciences, Bacterial Proteins, Genetics, Amino Acid Sequence, Molecular Biology, 030304 developmental biology, MESH: Cupriavidus, MESH: Molecular Sequence Data, Cupriavidus metallidurans, Ligand, Cell Biology, biology.organism_classification, MESH: Crystallography, X-Ray, Copper, 0104 chemical sciences, Protein Structure, Tertiary, Crystallography, chemistry, MESH: Dimerization, X-ray structure, Apoproteins, Derivative (chemistry), Heavy-metal, MESH: Periplasmic Proteins
Abstract

International audience; Both the X-ray structures of the apo- and the copper-bound forms of the metal-sensor domain (residues 31-148) of CnrX from Cupriavidus metallidurans CH34 were obtained at 1.74A resolution from a selenomethionine derivative. This four-helix hooked-hairpin is the first structure of a metal-sensor in an ECF-type signaling pathway. The copper ion is bound in a type 2-like center with a 3N1O coordination in the equatorial plane and shows an unprecedented remote fifth axial ligand with Met93 contributing a weak S-Cu bond. The signal onset cannot be explained by conformational changes associated with CnrX metallation.

Published
2008
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46. Deregulation of the SecYEG Translocation Channel upon Removal of the Plug Domain

Author

Antoine P. Maillard, Shifana Lalani, Filo Silva, Franck Duong, Dominique Belin, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Hemostase, Endothelium, Angiogenese (UMR_S_553), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris-Sud - Paris 11 (UP11), and University of British Columbia (UBC)

Subjects
Signal peptide, Protein subunit, Chromosomal translocation, Gating, ddc:616.07, Bioinformatics, Membrane Proteins/chemistry/metabolism, Biochemistry, Protein Structure, Secondary, law.invention, Protein Transport/physiology, 03 medical and health sciences, Escherichia coli/ metabolism, law, Multiprotein Complexes/ chemistry/ metabolism, Escherichia coli, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Protein Structure, Quaternary, Spark plug, Molecular Biology, 030304 developmental biology, 0303 health sciences, Crystallography, Membrane insertion, Chemistry, Escherichia coli Proteins, Escherichia coli Proteins/ chemistry/ metabolism, 030302 biochemistry & molecular biology, Membrane Proteins, Cell Biology, Translocon, Protein Structure, Tertiary, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], Protein Transport, Membrane, Multiprotein Complexes, Biophysics, Additions and Corrections, SEC Translocation Channels
Abstract

International audience; Previous studies have shown that the SecY plug is displaced from the center of the SecYEG channel during polypeptide translocation. The structural and functional consequences of the deletion of the plug are now examined. Both in vivo and in vitro observations indicate that the plug domain is not essential to the function of the translocon. In fact, deletion of the plug confers to the cell and to the membranes a Prl-like phenotype: reduced proton-motive force dependence of translocation, increased membrane insertion of SecA, diminished requirement for functional leader peptide, and weakened SecYEG subunit association. Although the plug domain does not seem essential, locking the plug in the center of the channel inactivates the translocon. Thus, the SecY plug is important to regulate the activity of the channel and to confer specificity to the translocation reaction. We propose that the plug contributes to the gating mechanism of the channel by maintaining the structure of the SecYEG complex in a compact closed state.

Published
2007
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47. Investigating the SecY plug movement at the SecYEG translocation channel

Author

Franck Duong, Patrick Tam, Kenneth K. Chan, Antoine P. Maillard, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)

Subjects
Protein subunit, Blotting, Western, Gating, General Biochemistry, Genetics and Molecular Biology, Article, 03 medical and health sciences, Protein structure, Escherichia coli, Translocase, Cysteine, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Molecular Biology, 030304 developmental biology, 0303 health sciences, General Immunology and Microbiology, biology, Membrane transport protein, General Neuroscience, Escherichia coli Proteins, 030302 biochemistry & molecular biology, Membrane Proteins, Membrane Transport Proteins, Translocon, Transport protein, Protein Structure, Tertiary, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], Protein Transport, Cross-Linking Reagents, Biochemistry, Multiprotein Complexes, biology.protein, Biophysics, Mutagenesis, Site-Directed, Electrophoresis, Polyacrylamide Gel, SEC Translocation Channels, Dimerization
Abstract

International audience; Protein translocation occurs across the energy-conserving bacterial membrane at the SecYEG channel. The crystal structure of the channel has revealed a possible mechanism for gating and opening. This study evaluates the plug hypothesis using cysteine crosslink experiments in combination with various allelic forms of the Sec complex. The results demonstrate that the SecY plug domain moves away from the center of the channel toward SecE during polypeptide translocation, and further show that the translocation-enhancing prlA3 mutation and SecG subunit change the properties of channel gating. Locking the plug in the open state preactivates the Sec complex, and a super-active translocase can be created when combined with the prlA4 mutation located in the pore of the channel. Dimerization of the Sec complex, which is essential for translocase activity, relocates the plug toward the open position. We propose that oligomerization may result in SecYEG cooperative interactions important to prime the translocon function.

Published
2005
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48. The V Antigen of Pseudomonas aeruginosa Is Required for Assembly of the Functional PopB/PopD Translocation Pore in Host Cell Membranes

Author

Jacqueline Chabert, Eric Faudry, Julien Goure, Alexandrine Pastor, Ina Attree, Andréa Dessen, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Groupe Pathogénie Bactérienne (IBS-PATBAC ), Institut de biologie structurale (IBS - UMR 5075 ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Faudry, Eric, and Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)

Subjects
Pore Forming Cytotoxic Proteins, Erythrocytes, Immunoprecipitation, Operon, Immunology, Mutant, Bacterial Toxins, Biology, Microbiology, Hemolysis, Green fluorescent protein, 03 medical and health sciences, Mice, Bacterial Proteins, medicine, Animals, Humans, Secretion, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], [SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Actin, 030304 developmental biology, 0303 health sciences, Antigens, Bacterial, 030306 microbiology, Effector, Erythrocyte Membrane, Biological Transport, Gene Expression Regulation, Bacterial, medicine.disease, Molecular biology, Molecular Pathogenesis, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Cell biology, Infectious Diseases, Pseudomonas aeruginosa, NIH 3T3 Cells, Parasitology, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Abstract

Pseudomonas aeruginosa efficiently intoxicates eukaryotic cells through the activity of the type III secretion-translocation system (TTSS). Gene deletions within the translocation operon pcrGVH-popBD abolish pore-forming activity of P. aeruginosa strains with macrophages and TTSS-dependent hemolysis. Here we investigated the requirements for PcrV, PopB, and PopD in pore formation by analyzing specific mutants using red blood cells (RBCs) and fibroblasts expressing green fluorescent protein fused to actin. Simultaneous secretion of three proteins, PopB, PopD, and PcrV, was required to achieve wild-type hemolysis and effector translocation. Deletion of pcrV in a cytotoxic strain did not affect secretion of PopB and PopD but abolished hemolytic activity and translocation of effectors into fibroblasts. Notably, the PcrV-deficient mutant was not capable of inserting PopD into host cell membranes, whereas PopB and PopD, but not PcrV, were readily found within membranes of wild-type-infected RBCs. Immunoprecipitation experiments performed by using a liposome model of pore assembly revealed a direct interaction between PopD and PopB but not between PopD and PcrV. Consequently, PcrV is necessary for the functional assembly of the PopB/D translocon complex but does not interact directly with pore-forming Pop proteins.

Published
2004
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49. Crystal Structures of Weissella viridescens FemX and Its Complex with UDP-MurNAc-Pentapeptide: Insights into FemABX Family Substrates Recognition

Author

Claudine Mayer, Sabrina Biarrotte-Sorin, Jean Delettré, Wladimir Sougakoff, Antoine P. Maillard, Michel Arthur, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de minéralogie, cristallographie de Paris (LMCP), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre d'Immunologie et de Maladies Infectieuses (CIMI), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre de Recherche des Cordeliers (CRC), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris Diderot - Paris 7 (UPD7), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
Models, Molecular, Protein family, Stereochemistry, MESH: Sequence Homology, Amino Acid, Nitrogenous Group Transferases, [SDV]Life Sciences [q-bio], Molecular Sequence Data, MESH: Amino Acid Sequence, MESH: Nitrogenous Group Transferases, Biology, Crystallography, X-Ray, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, MESH: Protein Structure, Tertiary, Bacterial Proteins, Structural Biology, MESH: Leuconostoc, Transferase, Amino Acid Sequence, Binding site, Molecular Biology, MESH: Bacterial Proteins, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, DNA ligase, MESH: Molecular Sequence Data, Sequence Homology, Amino Acid, 010405 organic chemistry, MESH: Crystallography, X-Ray, Uridine Diphosphate N-Acetylmuramic Acid, Protein Structure, Tertiary, 0104 chemical sciences, Amino acid, carbohydrates (lipids), chemistry, Biochemistry, Docking (molecular), Transfer RNA, MESH: Uridine Diphosphate N-Acetylmuramic Acid, Peptidoglycan, Leuconostoc, MESH: Models, Molecular
Abstract

International audience; Members of the FemABX protein family are novel therapeutic targets, as they are involved in the synthesis of the bacterial cell wall. They catalyze the addition of amino acid(s) on the peptidoglycan precursor using aminoacylated tRNA as a substrate. We report here the high-resolution structure of Weissella viridescens L-alanine transferase FemX and its complex with the UDP-MurNAc-pentapeptide. This is the first structure example of a FemABX family member that does not possess a coiled-coil domain. FemX consists of two structurally equivalent domains, separated by a cleft containing the binding site of the UDP-MurNAc-pentapeptide and a long channel that traverses one of the two domains. Our structural studies bring new insights into the evolution of the FemABX and the related GNAT superfamilies, shed light on the recognition site of the aminoacylated tRNA in Fem proteins, and allowed manual docking of the acceptor end of the alanyl-tRNAAla.

Published
2004
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50. Crystallization and preliminary X-ray analysis of Weissella viridescens FemX UDP-MurNAc-pentapeptide:l-alanine ligase

Author

Wladimir Sougakoff, Sabrina Biarrotte-Sorin, Didier Blanot, Jean Delettré, Michel Arthur, Antoine P. Maillard, Jean-Emmanuel Hugonnet, Claudine Mayer, Karine Blondeau, Pathogenèse bactérienne et réponses cellulaires (PBRC), Biologie du Cancer et de l'Infection (BCI ), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de minéralogie, cristallographie de Paris (LMCP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Centre d'Immunologie et de Maladies Infectieuses (CIMI), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de génétique et microbiologie [Orsay] (IGM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche des Cordeliers (CRC), Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris Diderot - Paris 7 (UPD7), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV]Life Sciences [q-bio], chemistry.chemical_element, Biology, medicine.disease_cause, Crystallography, X-Ray, 03 medical and health sciences, chemistry.chemical_compound, X-Ray Diffraction, Structural Biology, medicine, Escherichia coli, Peptide Synthases, 030304 developmental biology, MESH: Crystallization, chemistry.chemical_classification, Alanine, 0303 health sciences, DNA ligase, Bacteria, 030306 microbiology, MESH: Escherichia coli, Resolution (electron density), MESH: X-Ray Diffraction, MESH: Chromatography, Gel, General Medicine, MESH: Crystallography, X-Ray, MESH: Peptide Synthases, Matrix-assisted laser desorption/ionization, Crystallography, MESH: Bacteria, Enzyme, chemistry, MESH: Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Chromatography, Gel, Peptidoglycan, Crystallization, Selenium
Abstract

International audience; Synthesis of the cell-wall peptidoglycan of firmicutes involves a unique family of peptide-bond-forming enzymes that use amino-acyl-tRNAs as substrates and are referred to as Fem proteins as they are factors essential for methicillin resistance in Staphylococcus aureus. The FemX UDP-MurNAc-pentapeptide:l-alanine ligase of Weissella viridescens was overexpressed, purified and crystallized. Native data were collected to 1.7 A resolution. The crystals belong to space group P2(1), with unit-cell parameters a = 42.03, b = 99.92, c = 45.84 A, beta = 116.02 degrees. The asymmetric unit contains one molecule. A selenium-derivative data set has been collected to 2.1 A resolution at the peak wavelength of the selenium absorption edge. Six strong selenium positions were visible in the anomalous Patterson map. Three additional weaker Se atoms have been identified by anomalous Fourier synthesis.

Published
2002
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