432 results on '"Cord factor"'
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2. 大肠杆菌表面展示结核分枝杆菌 噬菌体结合肽.
- Author
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孙曼銮, 葛 赛, 卜 佳, and 高 强
- Abstract
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- Published
- 2021
- Full Text
- View/download PDF
3. Lack of methoxy-mycolates characterizes the geographically restricted lineage 7 of Mycobacterium tuberculosis complex
- Abstract
Lineage 7 (L7) emerged in the phylogeny of the Mycobacterium tuberculosis complex (MTBC) subsequent to the branching of 'ancient' lineage 1 and prior to the Eurasian dispersal of 'modern' lineages 2, 3 and 4. In contrast to the major MTBC lineages, the current epidemiology suggests that prevalence of L7 is highly confined to the Ethiopian population, or when identified outside of Ethiopia, it has mainly been in patients of Ethiopian origin. To search for microbiological factors that may contribute to its restricted distribution, we compared the genome of L7 to the genomes of globally dispersed MTBC lineages. The frequency of predicted functional mutations in L7 was similar to that documented in other lineages. These include mutations characteristic of modern lineages - such as constitutive expression of nitrate reductase - as well as mutations in the VirS locus that are commonly found in ancient lineages. We also identified and characterized multiple lineage-specific mutations in L7 in biosynthesis pathways of cell wall lipids, including confirmed deficiency of methoxy-mycolic acids due to a stop-gain mutation in the mmaA3 gene that encodes a methoxy-mycolic acid synthase. We show that the abolished biosynthesis of methoxy-mycolates of L7 alters the cell structure and colony morphology on selected growth media and impacts biofilm formation. The loss of these mycolic acid moieties may change the host-pathogen dynamic for L7 isolates, explaining the limited geographical distribution of L7 and contributing to further understanding the spread of MTBC lineages across the globe.
- Published
- 2023
4. Lack of methoxy-mycolates characterizes the geographically restricted lineage 7 of Mycobacterium tuberculosis complex
- Author
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Elena Hailu, Daire Cantillon, Carlos Madrazo, Graham Rose, Paul R. Wheeler, Paul Golby, Bethlehem Adnew, Sebastien Gagneux, Abraham Aseffa, Stephen V. Gordon, Iñaki Comas, Douglas B. Young, Simon J. Waddell, Gerald Larrouy-Maumus, Stefan Berg, National Institutes of Health (US), African Society of Human genetics, Science for Africa, and Comas, Iñaki
- Subjects
Model organisms ,Lineage 7 ,Cell wall ,FOS: Clinical medicine ,Immunology ,Methoxy-mycolates ,Infectious Disease ,Mycobacterium tuberculosis ,Genomics ,General Medicine ,Cord factor ,Computational & Systems Biology - Abstract
16 páginas, 6 figuras, 2 tablas, Lineage 7 (L7) emerged in the phylogeny of the Mycobacterium tuberculosis complex (MTBC) subsequent to the branching of 'ancient' lineage 1 and prior to the Eurasian dispersal of 'modern' lineages 2, 3 and 4. In contrast to the major MTBC lineages, the current epidemiology suggests that prevalence of L7 is highly confined to the Ethiopian population, or when identified outside of Ethiopia, it has mainly been in patients of Ethiopian origin. To search for microbiological factors that may contribute to its restricted distribution, we compared the genome of L7 to the genomes of globally dispersed MTBC lineages. The frequency of predicted functional mutations in L7 was similar to that documented in other lineages. These include mutations characteristic of modern lineages - such as constitutive expression of nitrate reductase - as well as mutations in the VirS locus that are commonly found in ancient lineages. We also identified and characterized multiple lineage-specific mutations in L7 in biosynthesis pathways of cell wall lipids, including confirmed deficiency of methoxy-mycolic acids due to a stop-gain mutation in the mmaA3 gene that encodes a methoxy-mycolic acid synthase. We show that the abolished biosynthesis of methoxy-mycolates of L7 alters the cell structure and colony morphology on selected growth media and impacts biofilm formation. The loss of these mycolic acid moieties may change the host-pathogen dynamic for L7 isolates, explaining the limited geographical distribution of L7 and contributing to further understanding the spread of MTBC lineages across the globe., This study was supported by the MRC Confidence in Concept Fund and the ISSF Wellcome Trust grants 105603/Z/14/Z (G.L-M) and 204833/Z/16/Z (S.J.W). E.H., A.A. and S.J.W. would like to acknowledge funding from the Association of Physicians of Great Britain and Ireland Links with Developing Countries Scheme, and the Human Hereditary and Health in Africa (H3Africa) ‘TBGEN: an integrated approach to unravelling susceptibility to tuberculosis in Africa’ [H3A/18/003]. H3Africa is managed by the Science for Africa (SFA) Foundation in partnership with the Wellcome Trust, the NIH (National Institutes of Health) and African Society of Human genetics (AfSHG). The views expressed herein are those of the authors and not necessarily those of the SFA Foundation and its partners.
- Published
- 2023
5. A single synthetic lipid antigen for improved serological diagnosis of Buruli ulcer.
- Author
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Hacking J, Gwenin VV, Dacombe RJ, Baird MS, Frimpong M, Phillips RO, and Gwenin CD
- Abstract
Setting: The diagnosis of Buruli ulcer (BU) is frequently made by experienced health workers in rural regions. This leads to long turnaround times to confirm the diagnosis as it requires specialised laboratory infrastructure to perform confirmatory testing., Background: Given the lack of success with protein antigens to detect BU in human sera, the aim of this study was to evaluate a range of single synthetic lipid antigens using an enzyme-linked immunosorbent assay (ELISA). The ELISA system used was initially developed to detect TB using single synthetic lipid antigens., Methods: Thirty polymerase chain reaction (PCR) positive BU samples and 30 PCR-negative healthy contact samples collected from Asante Akim North and Ahafo Ano North Districts, Ghana, that are endemic for BU between 2013 and 2016 were used to evaluate the synthetic lipid antigen ELISA. A Quantikine ELISA was also conducted on a randomly blinded sub-set of 30 samples., Results: The synthetic lipid ELISA evaluated here outperforms all other ELISA tests using protein antigens to detect BU to date and has shown potential as a fast (2 h) test for BU which may be adapted for use at the point of care. A sensitivity of 63% and specificity of 80% was observed for 30 BU-positive and 30 BU-negative samples, with significantly reduced interleukin-8 (IL-8) levels in a subset of patients with BU., Conclusion: A single lipid was shown for the first time to have the ability to distinguish between PCR-positive BU and negative sera using ELISA. The low lipid antibody load detected may be a result of immune suppression caused by the presence of mycolactone in patients with BU, given that levels of IL-8 were significantly reduced in patients with BU compared to the control serum samples., (© 2023 The Union.)
- Published
- 2023
- Full Text
- View/download PDF
6. Mycobacterial trehalose 6,6′-dimycolate induced vascular occlusion is accompanied by subendothelial inflammation.
- Author
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Hwang, Shen-An, Byerly, Caitlan D., and Actor, Jeffrey K.
- Abstract
Mycobacterium tuberculosis (MTB) is a pathogen that infects and kills millions yearly. The mycobacterium's cell wall glycolipid trehalose 6,6′-dimycolate (TDM) has been used historically to model MTB induced inflammation and granuloma formation. Alterations to the model can significantly influence the induced pathology. One such method incorporates intraperitoneal pre-exposure, after which the intravenous injection of TDM generates pathological damage effectively mimicking the hypercoagulation, thrombus formation, and tissue remodeling apparent in lungs of infected individuals. The purpose of these experiments is to examine the histological inflammation involved in the TDM mouse model that induces development of the hemorrhagic response. TDM induced lungs of C57BL/6 mice to undergo granulomatous inflammation. Further histological examination of the peak response demonstrated tissue remodeling consistent with hypercoagulation. The observed vascular occlusion indicates that obstruction likely occurs due to subendothelial localized activity leading to restriction of blood vessel lumens. Trichrome staining revealed that associated damage in the hypercoagulation model is consistent with intra endothelial cell accumulation of innate cells, bordered by collagen deposition in the underlying parenchyma. Overall, the hypercoagulation model represents a comparative pathological instrument for understanding mechanisms underlying development of hemorrhage and vascular occlusion seen during MTB infection. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
7. CONCORDÂNCIA INTEROBSERVADORES DA DETECÇÃO DO FATOR CORDA PARA A IDENTIFICAÇÃO PRESUNTIVA DO MYCOBACTERIUM TUBERCULOSIS.
- Author
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Marques Franco, Paulo Henrique, Yukari Ueno, Priscilla, Adélia Fernandes, Daniela, Silva de Aguiar, Amanda Aparecida, Rafael Teixeira, Regina, dos Santos de Barros Lordelo, André, Chiari Galle, Leonilda, and Peresi Lordelo, Eliana
- Abstract
Detection of cord factor may favor the definitive diagnosis and initiation of antituberculosis treatment. The aim of this study was to evaluate the interobserver concordance of mycobacterial smears stained with Ziehl-Neelsen technique for the presumptive identification of the Mycobacterium tuberculosis (M. tuberculosis). Three observers, healthcare students, conducted a blind reading of 30 slides stained with Ziehl-Neelsen and their results were compared to the results of an experient reader. Kappa coefficient with 95% interval was used to evaluate the concordance between the readings. No excellent interobserver concordance (α>0.75) was found. The interpretation and use of the cord factor for the presumptive identification of the M. tuberculosis is a technique that requires training for the interpretation of the variables of the smear stained with Ziehl-Neelsen technique and theoretical knowledge of the observer to deliver a correct result. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
8. The role of corynomycolic acids in <italic>Corynebacterium</italic>-host interaction.
- Author
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Burkovski, Andreas
- Abstract
Within the
Actinobacteria , the generaCorynebacterium ,Mycobacterium ,Nocardia andRhodococcus form the so-called CMNR group, also designated as mycolic acid-containing actinomycetes. Almost all members of this group are characterized by a mycolic acid layer, the mycomembrane, which covers the cell wall and is responsible for a high resistance of these bacteria against chemical and antibiotic stress. Furthermore, components of the mycomembrane are crucial for the interaction of bacteria with host cells. This review summarizes the current knowledge of mycolic acid synthesis and interaction with components of the immune system for the genusCorynebacterium with an emphasis on the pathogenic speciesCorynebacterium diphtheriae ,Corynebacterium pseudotuberculosis andCorynebacterium ulcerans as well as the biotechnology workhorseCorynebacterium glutamicum . [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
9. Lack of methoxy-mycolates characterizes the geographically restricted lineage 7 of Mycobacterium tuberculosis complex.
- Author
-
Hailu E, Cantillon D, Madrazo C, Rose G, Wheeler PR, Golby P, Adnew B, Gagneux S, Aseffa A, Gordon SV, Comas I, Young DB, Waddell SJ, Larrouy-Maumus G, and Berg S
- Subjects
- Humans, Mycolic Acids metabolism, Mutation, Phylogeny, Ethiopia epidemiology, Mycobacterium tuberculosis genetics
- Abstract
Lineage 7 (L7) emerged in the phylogeny of the Mycobacterium tuberculosis complex (MTBC) subsequent to the branching of 'ancient' lineage 1 and prior to the Eurasian dispersal of 'modern' lineages 2, 3 and 4. In contrast to the major MTBC lineages, the current epidemiology suggests that prevalence of L7 is highly confined to the Ethiopian population, or when identified outside of Ethiopia, it has mainly been in patients of Ethiopian origin. To search for microbiological factors that may contribute to its restricted distribution, we compared the genome of L7 to the genomes of globally dispersed MTBC lineages. The frequency of predicted functional mutations in L7 was similar to that documented in other lineages. These include mutations characteristic of modern lineages - such as constitutive expression of nitrate reductase - as well as mutations in the VirS locus that are commonly found in ancient lineages. We also identified and characterized multiple lineage-specific mutations in L7 in biosynthesis pathways of cell wall lipids, including confirmed deficiency of methoxy-mycolic acids due to a stop-gain mutation in the mmaA3 gene that encodes a methoxy-mycolic acid synthase. We show that the abolished biosynthesis of methoxy-mycolates of L7 alters the cell structure and colony morphology on selected growth media and impacts biofilm formation. The loss of these mycolic acid moieties may change the host-pathogen dynamic for L7 isolates, explaining the limited geographical distribution of L7 and contributing to further understanding the spread of MTBC lineages across the globe.
- Published
- 2023
- Full Text
- View/download PDF
10. Mycobacterial Cord Factor Reprograms the Macrophage Response to IFN-γ towards Enhanced Inflammation yet Impaired Antigen Presentation and Expression of GBP1
- Author
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Stefan Wirtz, Ulrike Schleicher, Elisabeth Naschberger, Veit Wiesmann, Barbara Killy, Alexander H. Dalpke, Barbara Bodendorfer, Arif B. Ekici, Jana Zimmer, Alexandra Huber, Roland Lang, Sushmita Paul, Julio Vera, and Nadine Grummel
- Subjects
Immunology ,Antigen presentation ,MHC Class II Gene ,Interferon-gamma ,Mice ,03 medical and health sciences ,Suppressor of Cytokine Signaling 1 Protein ,0302 clinical medicine ,GTP-Binding Proteins ,Gene expression ,Animals ,Humans ,Tuberculosis ,Immunology and Allergy ,Lectins, C-Type ,STAT1 ,Receptor ,Cells, Cultured ,Inflammation ,Mice, Knockout ,Antigen Presentation ,Cord factor ,biology ,Gene Expression Profiling ,Macrophages ,Pattern recognition receptor ,Membrane Proteins ,Mycobacterium tuberculosis ,Macrophage Activation ,Cell biology ,Mice, Inbred C57BL ,IRF1 ,biology.protein ,Cord Factors ,030215 immunology - Abstract
Mycobacteria survive in macrophages despite triggering pattern recognition receptors and T cell–derived IFN-γ production. Mycobacterial cord factor trehalose-6,6-dimycolate (TDM) binds the C-type lectin receptor MINCLE and induces inflammatory gene expression. However, the impact of TDM on IFN-γ–induced macrophage activation is not known. In this study, we have investigated the cross-regulation of the mouse macrophage transcriptome by IFN-γ and by TDM or its synthetic analogue trehalose-6,6-dibehenate (TDB). As expected, IFN-γ induced genes involved in Ag presentation and antimicrobial defense. Transcriptional programs induced by TDM and TDB were highly similar but clearly distinct from the response to IFN-γ. The glycolipids enhanced expression of a subset of IFN-γ–induced genes associated with inflammation. In contrast, TDM/TDB exerted delayed inhibition of IFN-γ–induced genes, including pattern recognition receptors, MHC class II genes, and IFN-γ–induced GTPases, with antimicrobial function. TDM downregulated MHC class II cell surface expression and impaired T cell activation by peptide-pulsed macrophages. Inhibition of the IFN-γ–induced GTPase GBP1 occurred at the level of transcription by a partially MINCLE-dependent mechanism that may target IRF1 activity. Although activation of STAT1 was unaltered, deletion of Socs1 relieved inhibition of GBP1 expression by TDM. Nonnuclear Socs1 was sufficient for inhibition, suggesting a noncanonical, cytoplasmic mechanism. Taken together, unbiased analysis of transcriptional reprogramming revealed a significant degree of negative regulation of IFN-γ–induced Ag presentation and antimicrobial gene expression by the mycobacterial cord factor that may contribute to mycobacterial persistence.
- Published
- 2020
11. Asymmetric Total Synthesis of Mycobacterial Diacyl Trehaloses Demonstrates a Role for Lipid Structure in Immunogenicity
- Author
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Georgios Misiakos, Ildiko Van Rhijn, David C. Young, D. Branch Moody, Mira Holzheimer, Adriaan J. Minnaard, Alexandrea K. Ramnarine, Eri Ishikawa, Tan-Yun Cheng, Sho Yamasaki, Josephine F. Reijneveld, and Chemical Biology 2
- Subjects
0301 basic medicine ,Chemical structure ,CORD FACTOR ,TUBERCULOSIS ,01 natural sciences ,Biochemistry ,GLYCOLIPIDS ,Mass Spectrometry ,ANTIGENS ,SULFOLIPID-I ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,Glycolipid ,Biosynthesis ,ACYLTREHALOSES ,Animals ,Humans ,Lectins, C-Type ,BIOSYNTHESIS ,Receptors, Immunologic ,Cord factor ,biology ,Molecular Structure ,010405 organic chemistry ,Immunogenicity ,ELUCIDATION ,Total synthesis ,Lectin ,Membrane Proteins ,Trehalose ,Stereoisomerism ,General Medicine ,Articles ,Mycobacterium tuberculosis ,0104 chemical sciences ,Trehalose dimycolate ,030104 developmental biology ,chemistry ,biology.protein ,T-CELLS ,Molecular Medicine ,VIRULENCE ,Chromatography, Liquid ,Protein Binding - Abstract
The first asymmetric total synthesis of three structures proposed for mycobacterial diacyl trehaloses, DAT1, DAT2, and DAT3 is reported. The presence of two of these glycolipids, DAT1 and DAT3, within different strains of pathogenic M. tuberculosis was confirmed, and it was shown that their abundance varies significantly. In mass spectrometry, synthetic DAT2 possessed almost identical fragmentation patterns to presumptive DAT2 from Mycobacterium tuberculosis H37Rv, but did not coelute by HPLC, raising questions as the precise relationship of the synthetic and natural materials. The synthetic DATs were examined as agonists for signaling by the C-type lectin, Mincle. The small differences in the chemical structure of the lipidic parts of DAT1, DAT2, and DAT3 led to drastic differences of Mincle binding and activation, with DAT3 showing similar potency as the known Mincle agonist trehalose dimycolate (TDM). In the future, DAT3 could serve as basis for the design of vaccine adjuvants with simplified chemical structure.
- Published
- 2020
12. Genetic determinants of virulence and drug resistance of Mycobacterium avium subsp. hominissuis — a causative agent of mycobacteriosis in humans
- Subjects
Cord factor ,biology ,Immunology ,Virulence ,Drug resistance ,biology.organism_classification ,Microbiology ,Multiple drug resistance ,Infectious Diseases ,Plasmid ,Immunology and Allergy ,Nontuberculous mycobacteria ,Gene ,Pathogen - Abstract
Among the members of the large group of non-tuberculous mycobacteria (comprising more than 180 species), M. avium subsp. hominissuis (MAH) is the most significant causative agent of pulmonary infection in immunocompetent individuals as well as disseminated infection in immunocompromised hosts, e.g. human immunodeficiency virus (HIV)-positive patients. Due to increased incidence rate of mycobacteriosis, especially in HIV infection, much still need to be learnt about the MAH genetic control and virulence mechanisms. Deciphering the genome contents of the M. avium strain 104 (isolated from an AIDS patient with disseminated MAH disease) allowed to compare genome sequences of M. avium strains to gain insights into genomic diversity associated with variable hosts and environments. Comparative genome analysis of MAH strains isolated from patients with pulmonary and disseminated forms of mycobacteri-osis revealed differences in the structure of the genome, affecting the key virulence genes. This review provides current data on the genetic determinants of MAH virulence associated with the initial phase of infection. Several mycobacterial virulence-associated gene families, such as mce (mammalian cell entry), mmp (mycobacterial membrane proteins), pe/ppe and esx expressed by MAH during human infection are thought to be crucial for adhesion, entry, survival, and reproduction inside host macrophages. The genetic mechanisms of MAH survival in human macrophage cell culture as well as mice exposed to toxic effects of reactive oxygen, nitric oxide, bactericidal proteins (cathelicidin) are discussed. The MAH survival in the latency-like state is important for pathogen dissemination. Some genetic and phenotypic features of MAH (absence of a cord factor, presence of plasmids, potential to “switch” morphological types of colonies) are compared with M. tuberculosis. In addition, we summarized current state of MAH drug discovery, a role of MAH intrinsic multidrug resistance, genetic control, as well as mechanisms underlying formation of resistance to various groups of antibiotics in MAH strains.
- Published
- 2020
13. Total Synthesis of a Mycolic Acid from Mycobacterium tuberculosis
- Author
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Dhineshkumar Jayaraman, Jeffrey Buter, Nabil Tahiri, D. Branch Moody, Martin D. Witte, Adriaan J. Minnaard, Tonatiuh A. Ocampo, Peter Fodran, Ildiko Van Rhijn, Chemical Biology 2, and Synthetic Organic Chemistry
- Subjects
Antigenicity ,T-Lymphocytes ,CD1b ,cross coupling ,Lymphocyte Activation ,010402 general chemistry ,01 natural sciences ,Catalysis ,Mycolic acid ,Antigens, CD1 ,Mycobacterium tuberculosis ,chemistry.chemical_compound ,Antigen ,mycolic acid ,Total Synthesis ,Moiety ,Research Articles ,chemistry.chemical_classification ,Cord factor ,biology ,010405 organic chemistry ,Cell Membrane ,Total synthesis ,Esters ,Stereoisomerism ,General Chemistry ,General Medicine ,biology.organism_classification ,Trehalose ,Tumor Necrosis Factor Receptor Superfamily, Member 7 ,0104 chemical sciences ,Glucose ,tuberculosis ,Mycolic Acids ,chemistry ,Biochemistry ,Research Article - Abstract
In Mycobacterium tuberculosis, mycolic acids and their glycerol, glucose, and trehalose esters (“cord factor”) form the main part of the mycomembrane. Despite their first isolation almost a century ago, full stereochemical evaluation is lacking, as is a scalable synthesis required for accurate immunological, including vaccination, studies. Herein, we report an efficient, convergent, gram‐scale synthesis of four stereo‐isomers of a mycolic acid and its glucose ester. Binding to the antigen presenting protein CD1b and T cell activation studies are used to confirm the antigenicity of the synthetic material. The absolute stereochemistry of the syn‐methoxy methyl moiety in natural material is evaluated by comparing its optical rotation with that of synthetic material., The total synthesis of four methoxy mycolic acid diastereomers is described. Key steps involve a Suzuki–Fu cross‐coupling, an anti‐selective Abiko–Masamune asymmetric aldol reaction, and an enantioselective Charette cyclopropanation. CD1b‐free mycolic acid tetramer staining experiments clearly favoured one diastereomer over the other three.
- Published
- 2020
14. Diagnosis of tuberculosis based on the detection of a cocktail of mycobacterial antigen 85B, ESAT-6 and cord factor by immuno-PCR.
- Author
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Mehta, Promod K., Singh, Netrapal, Dharra, Renu, Dahiya, Bhawna, Sharma, Suman, Sheoran, Abhishek, Gupta, Krishna B., Chaudhary, Dhruva, Mehta, Neeru, and Varma-Basil, Mandira
- Subjects
- *
TUBERCULOSIS diagnosis , *TREHALOSE dimycolate , *POLYMERASE chain reaction , *ANTIGENS , *TUBERCULOSIS patients - Abstract
Attempts were made to enhance the sensitivity of immuno-PCR assay based on the detection of cocktail of mycobacterial antigen 85B (Rv1886c), ESAT-6 (Rv3875) and cord factor (trehalose 6,6′-dimycolate) in pulmonary and extrapulmonary TB patients. Detection of Ag85B was found to be superior to the detection of cocktail in TB patients. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
15. Serodiagnostic potential of immuno-PCR using a cocktail of mycobacterial antigen 85B, ESAT-6 and cord factor in tuberculosis patients.
- Author
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Singh, Netrapal, Sreenivas, Vishnubhatla, Sheoran, Abhishek, Sharma, Suman, Gupta, Krishna B., Khuller, Gopal K., and Mehta, Promod K.
- Subjects
- *
SERODIAGNOSIS , *POLYMERASE chain reaction , *MYCOBACTERIAL diseases , *BACTERIAL antigens , *TUBERCULOSIS patients - Abstract
A novel indirect immuno-polymerase chain reaction (I-PCR) assay was developed for the detection of circulating anti-Ag85B (antigen 85B, Rv1886c), anti-ESAT-6 (early secretory antigenic target-6, Rv3875) and anti-cord factor (trehalose 6,6′-dimycolate) antibodies from the sera samples of pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) patients and the results were compared with an analogous enzyme-linked immunosorbent assay (ELISA). We covalently attached the amino-modified reporter DNA to the dithiothreitol (DTT)-reduced anti-human IgG antibody through a chemical linker succinimidyl 4-[N-maleimidomethyl]-cyclohexane-1-carboxylate (SMCC). The detection of cocktail of anti-Ag85B, anti-ESAT-6 and anti-cord factor antibodies was found to be superior to the detection of individual antibodies. The sensitivities of 89.5% and 77.5% with I-PCR and 70.8% and 65% with ELISA were observed in smear-positive and smear-negative PTB cases, respectively with high specificity (90.9%). On the other hand, a sensitivity of 77.5% with I-PCR and 65% with ELISA was observed in EBTB cases. The detection of cocktail of antibodies by I-PCR is likely to improve the utility of existing algorithms for TB diagnosis. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
16. Molecular armory or niche factors: virulence determinants of Corynebacterium species.
- Author
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Tauch, Andreas and Burkovski, Andreas
- Subjects
- *
CORYNEBACTERIUM , *MICROBIAL virulence , *TREHALOSE dimycolate , *DIPHTHERIA toxin , *MYCOLIC acids , *PHOSPHOLIPASES , *VEROCYTOTOXINS - Abstract
For successful colonization of a host, pathogenic bacteria are equipped with a plethora of proteins and other components, often designated as virulence factors. However, many of these factors are involved in general adaptation to ecological niches rather than being specific for interaction of a bacterial pathogen with a distinct host. Therefore, a designation of these components as niche factors was proposed. While originally developed for different species colonizing the gastro-intestinal tract, in this communication the concept of niche factors is discussed in respect to a single genus, i.e. Corynebacterium species. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
17. Surface-shaving proteomics of mycobacterium marinum identifies biofilm subtype-specific changes affecting virulence, tolerance, and persistence
- Author
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Ilkka Miettinen, Henna Myllymäki, Lauri Paulamäki, Leena-Maija Vanha-aho, Mataleena Parikka, Adyary Fallarero, Tuula A. Nyman, Teemu O. Ihalainen, Hanna Luukinen, Kirsi Savijoki, Aleksandra Svorjova, Jari Yli-Kauhaluoma, Tampere University, BioMediTech, Division of Pharmaceutical Biosciences, Drug Research Program, Division of Pharmacology and Pharmacotherapy, Explorations of Anti Infectives, Pharmaceutical Design and Discovery group, Divisions of Faculty of Pharmacy, Jari Yli-Kauhaluoma / Principal Investigator, and Division of Pharmaceutical Chemistry and Technology
- Subjects
Multidrug tolerance ,Physiology ,PATHOGENESIS ,Virulence ,Biology ,Proteomics ,Biochemistry ,Microbiology ,biofilm matrix ,03 medical and health sciences ,cell surface proteomics ,MOONLIGHTING PROTEINS ,Genetics ,RECURRENT TUBERCULOSIS ,Secretion ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,Mycobacterium marinum ,030304 developmental biology ,0303 health sciences ,Cord factor ,tolerance ,318 Medical biotechnology ,030306 microbiology ,Biofilm matrix ,Biofilms ,Cell surface proteomics ,Persistence ,Tolerance ,Biofilm ,persistence ,bacterial infections and mycoses ,biology.organism_classification ,GENE ,QR1-502 ,EVOLUTION ,Computer Science Applications ,Bacterial adhesin ,317 Pharmacy ,Modeling and Simulation ,GROWTH ,Nontuberculous mycobacteria ,LACTOBACILLUS-CRISPATUS ,biofilms ,MEMBRANE ,SYNTHETASE ,MYCOLIC ACIDS ,Research Article - Abstract
The complex cell wall and biofilm matrix (ECM) act as key barriers to antibiotics in mycobacteria. Here, the ECM and envelope proteins of Mycobacterium marinum ATCC 927, a nontuberculous mycobacterial model, were monitored over 3 months by label-free proteomics and compared with cell surface proteins on planktonic cells to uncover pathways leading to virulence, tolerance, and persistence. We show that ATCC 927 forms pellicle-type and submerged-type biofilms (PBFs and SBFs, respectively) after 2 weeks and 2 days of growth, respectively, and that the increased CelA1 synthesis in this strain prevents biofilm formation and leads to reduced rifampicin tolerance. The proteomic data suggest that specific changes in mycolic acid synthesis (cord factor), Esx1 secretion, and cell wall adhesins explain the appearance of PBFs as ribbon-like cords and SBFs as lichen-like structures. A subpopulation of cells resisting 64× MIC rifampicin (persisters) was detected in both biofilm subtypes and already in 1-week-old SBFs. The key forces boosting their development could include subtype-dependent changes in asymmetric cell division, cell wall biogenesis, tricarboxylic acid/glyoxylate cycle activities, and energy/redox/iron metabolisms. The effect of various ambient oxygen tensions on each cell type and nonclassical protein secretion are likely factors explaining the majority of the subtype-specific changes. The proteomic findings also imply that Esx1-type protein secretion is more efficient in planktonic (PL) and PBF cells, while SBF may prefer both the Esx5 and nonclassical pathways to control virulence and prolonged viability/persistence. In conclusion, this study reports the first proteomic insight into aging mycobacterial biofilm ECMs and indicates biofilm subtype-dependent mechanisms conferring increased adaptive potential and virulence of nontuberculous mycobacteria., mSystems, 6 (3), ISSN:2379-5077
- Published
- 2021
18. Mycobacterial trehalose 6,6′-dimycolate induced vascular occlusion is accompanied by subendothelial inflammation
- Author
-
Caitlan D. Byerly, Shen-An Hwang, and Jeffrey K. Actor
- Subjects
0301 basic medicine ,Microbiology (medical) ,Pathology ,medicine.medical_specialty ,Granuloma, Respiratory Tract ,030106 microbiology ,Immunology ,Inflammation ,Vascular Remodeling ,Microbiology ,Vascular occlusion ,Article ,Masson's trichrome stain ,03 medical and health sciences ,Parenchyma ,Animals ,Medicine ,Blood Coagulation ,Lung ,Tuberculosis, Pulmonary ,Cord factor ,business.industry ,Mycobacterium tuberculosis ,Pneumonia ,medicine.disease ,Mice, Inbred C57BL ,Endothelial stem cell ,Disease Models, Animal ,030104 developmental biology ,Infectious Diseases ,medicine.anatomical_structure ,Granuloma ,Cord Factors ,Female ,Endothelium, Vascular ,medicine.symptom ,business ,Blood vessel - Abstract
Mycobacterium tuberculosis (MTB) is a pathogen that infects and kills millions yearly. The mycobacterium's cell wall glycolipid trehalose 6,6'-dimycolate (TDM) has been used historically to model MTB induced inflammation and granuloma formation. Alterations to the model can significantly influence the induced pathology. One such method incorporates intraperitoneal pre-exposure, after which the intravenous injection of TDM generates pathological damage effectively mimicking the hypercoagulation, thrombus formation, and tissue remodeling apparent in lungs of infected individuals. The purpose of these experiments is to examine the histological inflammation involved in the TDM mouse model that induces development of the hemorrhagic response. TDM induced lungs of C57BL/6 mice to undergo granulomatous inflammation. Further histological examination of the peak response demonstrated tissue remodeling consistent with hypercoagulation. The observed vascular occlusion indicates that obstruction likely occurs due to subendothelial localized activity leading to restriction of blood vessel lumens. Trichrome staining revealed that associated damage in the hypercoagulation model is consistent with intra endothelial cell accumulation of innate cells, bordered by collagen deposition in the underlying parenchyma. Overall, the hypercoagulation model represents a comparative pathological instrument for understanding mechanisms underlying development of hemorrhage and vascular occlusion seen during MTB infection.
- Published
- 2019
19. CONCORDÂNCIA INTEROBSERVADORES DA DETECÇÃO DO FATOR CORDA PARA A IDENTIFICAÇÃO PRESUNTIVA DO MYCOBACTERIUM TUBERCULOSIS
- Author
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Paulo Henrique Marques Franco, Amanda Aparecida Silva de Aguiar, André dos Santos de Barros Lordelo, Regina Rafael Teixeira, Leonilda Chiari Galle, Daniela Adélia Fernandes, Eliana Peresi Lordelo, and Priscilla Yukari Ueno
- Subjects
fator corda ,medicine.medical_specialty ,lcsh:R5-920 ,Cord factor ,Tuberculosis ,biology ,business.industry ,Concordance ,tuberculose ,bacterial infections and mycoses ,biology.organism_classification ,medicine.disease ,diagnóstico ,Mycobacterium tuberculosis ,fluids and secretions ,Cohen's kappa ,Internal medicine ,parasitic diseases ,medicine ,business ,lcsh:Medicine (General) ,concordância ,Earth-Surface Processes ,mycobacterium tuberculosis - Abstract
A detecção do fator corda pode favorecer o diagnóstico definitivo e início do tratamento antituberculose. O objetivo deste estudo foi avaliar a concordância interobservadores da leitura de esfregaços micobacterianos corados pela técnica de Ziehl-Neelsen para a identificação presuntiva do Mycobacterium tuberculosis (M. tuberculosis). Três observadores, estudantes da área da saúde, realizaram a leitura às cegas de 30 lâminas coradas pela técnica de Ziehl-Neelsen e seus resultados foram comparados com os de um observador experiente. Para avaliar a concordância entre as leituras foi realizado o Coeficiente Kappa com intervalo de confiança de 95%. Não foi observada nenhuma concordância excelente (κ > 0,75) interobservadores. A interpretação e utilização do fator corda para o diagnóstico presuntivo do M. tuberculosis é uma técnica que necessita de treinamento para interpretar as variáveis presentes nos esfregaços corados pela técnica de Ziehl-Neelsen e conhecimento teórico do observador para que o resultado possa ser proferido de forma correta.
- Published
- 2019
20. Discovery of Salmonella trehalose phospholipids reveals functional convergence with mycobacteria
- Author
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Sho Yamasaki, D. Branch Moody, Jacob A. Mayfield, Cécile A. van Els, Michael McClelland, Steffen Porwollik, Ildiko Van Rhijn, Gordon Dougan, Patrick J. Brennan, Eri Ishikawa, Adriaan J. Minnaard, Peter Reinink, Eva Heinz, Vivek K. Mishra, Tan-Yun Cheng, Jeffrey Buter, Peter Willemsen, Giorgio Napolitani, Vincenzo Cerundolo, Reinink, Peter [0000-0002-9836-1335], Buter, Jeffrey [0000-0002-4440-6702], Mishra, Vivek K [0000-0002-2121-6121], Cheng, Tan-Yun [0000-0002-5178-6985], Heinz, Eva [0000-0003-4413-3756], Dougan, Gordon [0000-0003-0022-965X], Cerundolo, Vincenzo [0000-0003-0040-3793], Minnaard, Adriaan J [0000-0002-5966-1300], Moody, D Branch [0000-0003-2306-3058], Van Rhijn, Ildiko [0000-0002-1446-5701], Apollo - University of Cambridge Repository, Synthetic Organic Chemistry, Chemical Biology 2, LS Immunologie, and dI&I RA-I&I I&I
- Subjects
0301 basic medicine ,LACTOBACILLIC ACID ,Salmonella ,EFFICIENT ,Transferases (Other Substituted Phosphate Groups) ,medicine.disease_cause ,Salmonella typhi ,CORD FACTOR ,01 natural sciences ,Medical and Health Sciences ,chemistry.chemical_compound ,Feces ,Mice ,Immunologic ,Lectins ,Receptors ,Cardiolipin ,Immunology and Allergy ,2.2 Factors relating to the physical environment ,Aetiology ,Receptors, Immunologic ,Research Articles ,IN-VIVO ,Phospholipids ,Phylogeny ,biology ,C-Type ,Bacteriologie ,Bacteriology, Host Pathogen Interaction & Diagnostics ,Foodborne Illness ,3. Good health ,Trehalose dimycolate ,ALIGNMENT ,Infectious Diseases ,MINCLE ,lipids (amino acids, peptides, and proteins) ,Infection ,Immunology ,News ,TUBERCULOSIS ,Insights ,Article ,Microbiology ,Mycobacterium ,Vaccine Related ,03 medical and health sciences ,Rare Diseases ,Transferases ,Biodefense ,medicine ,Escherichia coli ,Life Science ,Animals ,Humans ,Lectins, C-Type ,Typhoid Fever ,Host Pathogen Interaction & Diagnostics ,Cord factor ,010405 organic chemistry ,Prevention ,Cell Membrane ,RECOGNITION ,Membrane Proteins ,Trehalose ,Bacteriology ,biology.organism_classification ,Host Pathogen Interactie & Diagnostiek ,0104 chemical sciences ,030104 developmental biology ,Orphan Drug ,Emerging Infectious Diseases ,Good Health and Well Being ,chemistry ,Bacteriologie, Host Pathogen Interactie & Diagnostiek ,DIHYDROSTERCULIC ACID ,T-CELLS ,Digestive Diseases ,Bacteria - Abstract
This work describes the discovery, biosynthesis, and chemical synthesis of a previously unknown class of lipids, trehalose phospholipids, in pathogenic Salmonella species. Trehalose phospholipids stimulate the innate immune receptor Mincle, the receptor for the strong adjuvant mycobacterial cord factor., Salmonella species are among the world’s most prevalent pathogens. Because the cell wall interfaces with the host, we designed a lipidomics approach to reveal pathogen-specific cell wall compounds. Among the molecules differentially expressed between Salmonella Paratyphi and S. Typhi, we focused on lipids that are enriched in S. Typhi, because it causes typhoid fever. We discovered a previously unknown family of trehalose phospholipids, 6,6′-diphosphatidyltrehalose (diPT) and 6-phosphatidyltrehalose (PT). Cardiolipin synthase B (ClsB) is essential for PT and diPT but not for cardiolipin biosynthesis. Chemotyping outperformed clsB homology analysis in evaluating synthesis of diPT. DiPT is restricted to a subset of Gram-negative bacteria: large amounts are produced by S. Typhi, lower amounts by other pathogens, and variable amounts by Escherichia coli strains. DiPT activates Mincle, a macrophage activating receptor that also recognizes mycobacterial cord factor (6,6′-trehalose dimycolate). Thus, Gram-negative bacteria show convergent function with mycobacteria. Overall, we discovered a previously unknown immunostimulant that is selectively expressed among medically important bacterial species.
- Published
- 2019
21. Rapid diagnosis of pulmonary tuberculosis
- Author
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José Mauricio Hernéndez Sarmiento, Natalia Builes Restrepo, Gloria Isabel Mejéa, Elsa Zapata, Mary Alejandra Restrepo, and Jaime Robledo'
- Subjects
cord factor ,tuberculosis ,mgit ,thin layer agar ,Medicine - Abstract
INTRODUCTION: World Health Organization had estimated 9.4 million tuberculosis cases on 2009, with 1.7 million of deaths as consequence of treatment and diagnosis failures. Improving diagnostic methods for the rapid and timely detection of tuberculosis patients is critical to control the disease. The aim of this study was evaluating the accuracy of the cord factor detection on the solid medium Middlebrook 7H11 thin layer agar compared to the Lowenstein Jensen medium for the rapid tuberculosis diagnosis. METHODS: Patients with suspected tuberculosis were enrolled and their sputum samples were processed for direct smear and culture on Lowenstein Jensen and BACTEC MGIT 960, from which positive tubes were subcultured on Middlebrook 7H11 thin layer agar. Statistical analysis was performed comparing culture results from Lowenstein Jensen and the thin layer agar, and their corresponding average times for detecting Mycobacterium tuberculosis. The performance of cord factor detection was evaluated determining its sensitivity, specificity, positive and negative predictive value. RESULTS: 111 out of 260 patients were positive for M. tuberculosis by Lowenstein Jensen medium with an average time '' standard deviation for its detection of 22.3 , 8.5 days. 115 patients were positive by the MGIT system identifying the cord factor by the Middlebrook 7H11 thin layer agar which average time standard deviation was 5.5 , 2.6 days. CONCLUSION: The cord factor detection by Middlebrook 7H11 thin layer agar allows early and accurate tuberculosis diagnosis during an average time of 5 days, making this rapid diagnosis particularly important in patients with negative sputum smear.
- Published
- 2014
- Full Text
- View/download PDF
22. MCL and mincle: C-type lectin receptors that sense damaged self and pathogen associated molecular patterns
- Author
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Mark B Richardson and Spencer J Williams
- Subjects
Glycolipids ,cord factor ,Mincle ,C-type lectin receptors ,MCL ,Immunologic diseases. Allergy ,RC581-607 - Abstract
MCL (macrophage C-type lectin) and mincle (macrophage inducible C-type lectin) comprise part of an extensive repertoire of pattern recognition receptors with the ability to sense damage associated and pathogen associated molecular patterns. In this review we cover the discovery and molecular characterization of these C-type lectin receptors, and highlight recent advances in the understanding of their roles in orchestrating the response of the immune system to bacterial and fungal infection, and damaged self. We also discuss the identification and structure-activity relationships of activating ligands, particularly trehalose dimycolate (TDM) and related mycobacterial glycolipids, which have significant potential in the development of TH1/TH17 vaccination strategies.
- Published
- 2014
- Full Text
- View/download PDF
23. Anti-Tuberculosis Activity in Punica granatum: In silico Validation and Identification of Lead Molecules
- Author
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Shefin Basheera, S. Sivan, and B. C. Kamalan
- Subjects
Drug ,Cord factor ,biology ,media_common.quotation_subject ,In silico ,biology.organism_classification ,Mycobacterium tuberculosis ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Phytochemical ,Docking (molecular) ,Punica ,Lead compound ,media_common - Abstract
Discovery of novel drug against tuberculosis is inevitable since resistant bacterial strains are evolved against existing drugs and rapidly active single drug in short period is necessary for effective treatment. When compared to synthetic drugs, natural drugs particularly phytochemicals induce less side effects and long term stability. In Indian traditional medicine, several plant species have been used for treating tuberculosis and each plant species contains a plethora of phytochemicals. The efficacy of such treatment system and identification of the phytochemical with drug activity from plants has been seldom investigated scientifically. In this backdrop, the authors have validated the efficacy of anti-tuberculosis activity and identified lead molecule from a widely used plant species against several disease including tuberculosis, viz Punica granatum L. The four promising target proteins viz mycolyltransferase antigen protein 85C involved in cord factor synthesis, filamentous temperature sensitive protein Z involved in bacterial cell division, pantothenate kinase involved in co-enzyme A pathway and decaprenylphosphoryl β-D-ribofuranose-2 epimerase involved in the synthesis of virulent factor arabinan were docked with 243 phytochemicals derived from Punica granatum. The docked molecules having binding energy ≤-6 kcal/ mol were considered as active/hit molecules. The docked results showed that out of 243 phytochemicals, 126 have inhibitory activity on all selected target proteins. Further docking study using Glide and absorption, distribution, metabolism, excretion and toxicity studies revealed that the compound derived from the lowers, pomegranatate can be recommended as the best lead compound against tuberculosis.
- Published
- 2021
24. Synthetic trehalose esters of cis-alkene and diene α′-mycolic acids of Mycobacteria.
- Author
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Taher, Salam G., Muzael, Maged, Al Dulayymi, Juma’a R., and Baird, Mark S.
- Subjects
- *
TREHALOSE , *MYCOLIC acids , *ESTERS , *CHEMICAL synthesis , *ALKENES , *DIOLEFINS , *MYCOBACTERIA - Abstract
The synthesis of an α′-mycolic acid of Mycobacterium smegmatis and other mycobacteria, containing a cis,cis -diene, and of the trehalose mono- and di-mycolates of this, and of a related α′-mycolic acid containing one cis -alkene, is reported. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
25. Recognition of the mycobacterial cord factor by Mincle: relevance for granuloma formation and resistance to tuberculosis
- Author
-
Roland eLang
- Subjects
Tuberculosis ,mycobacteria ,cord factor ,TDM ,Mincle ,C-type lectin receptor ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The world’s most successful intracellular bacterial pathogen, Mycobacterium tuberculosis (MTB), survives inside macrophages by blocking phagosome maturation and establishes chronic infection characterized by the formation of granulomas. Trehalose-6,6-dimycolate (TDM), the mycobacterial cord factor, is the most abundant cell wall lipid of virulent mycobacteria, is sufficient to cause granuloma formation, and has long been known to be a major virulence factor of MTB. Recently, TDM has been shown to activate the Syk-Card9 signaling pathway in macrophages through binding to the C-type lectin receptor Mincle. The Mincle-Card9 pathway is required for activation of macrophages by TDM in vitro and for granuloma formation in vivo following injection of TDM. Whether this pathway is also exploited by MTB to reprogram the macrophage into a comfortable niche has not been explored yet. Several recent studies have investigated the phenotype of Mincle-deficient mice in mycobacterial infection, yielding divergent results in terms of a role for Mincle in host resistance. Here, we review these studies, discuss possible reasons for discrepant results and highlight open questions in the role of Mincle and other C-type lectin receptors in the infection biology of MTB.
- Published
- 2013
- Full Text
- View/download PDF
26. The role of corynomycolic acids in Corynebacterium-host interaction
- Author
-
Burkovski, Andreas
- Published
- 2018
- Full Text
- View/download PDF
27. MCL and Mincle: C-type lectin receptors that sense damaged self and pathogen-associated molecular patterns.
- Author
-
Richardson, Mark B. and Williams, Spencer J.
- Subjects
MACROPHAGES ,LECTINS ,PATTERN perception ,IMMUNE system ,MYCOSES ,LIGANDS (Biochemistry) ,VACCINATION ,GLYCOLIPIDS - Abstract
Macrophage C-type lectin (MCL) and macrophage inducible C-type lectin (Mincle) comprise part of an extensive repertoire of pattern recognition receptors with the ability to sense damage-associated and pathogen-associated molecular patterns. In this review, we cover the discovery and molecular characterization of these C-type lectin receptors, and highlight recent advances in the understanding of their roles in orchestrating the response of the immune system to bacterial and fungal infection, and damaged self. We also discuss the identification and structure-activity relationships of activating ligands, particularly trehalose dimycolate and related mycobacterial glycolipids, which have significant potential in the development of T
H 1/TH 17 vaccination strategies. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
28. Rapid diagnosis of pulmonary tuberculosis.
- Author
-
Sarmiento, José Mauricio Hernández, Restrepo, Natalia Builes, Mejía, Gloria Isabel, Zapata, Elsa, Restrepo, Mary Alejandra, and Robledo, Jaime
- Subjects
- *
TUBERCULOSIS diagnosis , *SPUTUM examination - Abstract
Introduction: World Health Organization had estimated 9.4 million tuberculosis cases on 2009, with 1.7 million of deaths as consequence of treatment and diagnosis failures. Improving diagnostic methods for the rapid and timely detection of tuberculosis patients is critical to control the disease. The aim of this study was evaluating the accuracy of the cord factor detection on the solid medium Middlebrook 7H11 thin layer agar compared to the Lowenstein Jensen medium for the rapid tuberculosis diagnosis. Methods: Patients with suspected tuberculosis were enrolled and their sputum samples were processed for direct smear and culture on Lowenstein Jensen and BACTEC MGIT 960, from which positive tubes were subcultured on Middlebrook 7H11 thin layer agar. Statistical analysis was performed comparing culture results from Lowenstein Jensen and the thin layer agar, and their corresponding average times for detecting Mycobacterium tuberculosis. The performance of cord factor detection was evaluated determining its sensitivity, specificity, positive and negative predictive value. Results: 111 out of 260 patients were positive for M. tuberculosis by Lowenstein Jensen medium with an average time ± standard deviation for its detection of 22.3 ± 8.5 days. 115 patients were positive by the MGIT system identifying the cord factor by the Middlebrook 7H11 thin layer agar which average time ± standard deviation was 5.5 ± 2.6 days. Conclusion: The cord factor detection by Middlebrook 7H11 thin layer agar allows early and accurate tuberculosis diagnosis during an average time of 5 days, making this rapid diagnosis particularly important in patients with negative sputum smear. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
29. Immune Recognition of Pathogen-Derived Glycolipids Through Mincle
- Author
-
Sho Yamasaki and Yasunobu Miyake
- Subjects
Cord factor ,Lectin ,Biology ,biology.organism_classification ,Microbiology ,03 medical and health sciences ,0302 clinical medicine ,Glycolipid ,Immunity ,biology.protein ,Macrophage ,030212 general & internal medicine ,Receptor ,Candida albicans ,Function (biology) - Abstract
Mincle (macrophage inducible C-type lectin, Clec4e, Clecsf9) was originally identified as a member of the C-type lectin receptor family in 1999. Then, the function of Mincle to control antifungal immunity by binding to Candida albicans was reported in 2008. Around the same time, it was reported that Mincle recognized damaged cells and induced sterile inflammation by coupling with the ITAM-adaptor molecule FcRγ. In the following year, a breakthrough discovery reported that Mincle was an essential receptor for mycobacterial cord factor (trehalose-6,6′-dimycolate, TDM). Mincle gained increasing attention immediately after this critical finding. Although our understanding of the recognition of Mycobacteria has been advanced significantly, it was also revealed that Mincle interacts with pathogens other than Mycobacteria. In addition, endogenous ligands of Mincle were identified recently. Therefore, Mincle is now considered a danger receptor both for self and non-self ligands, so-called damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs). This chapter will give an overview of the accumulated knowledge of the multi-task danger receptor Mincle from its discovery to the latest findings.
- Published
- 2020
30. Impact of Aging and HIV Infection on the Function of the C-Type Lectin Receptor MINCLE in Monocytes
- Author
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Sui Tsang, Stefan Avey, Heidi J Zapata, Barbara Siconolfi, Albert C. Shaw, Lydia Barakat, Peter H. Van Ness, Subhasis Mohanty, Jean H. Wilson, and Heather G. Allore
- Subjects
Adult ,Male ,0301 basic medicine ,Aging ,HIV Infections ,Peripheral blood mononuclear cell ,Monocytes ,Cohort Studies ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,C-type lectin ,Humans ,Medicine ,Lectins, C-Type ,Receptors, Immunologic ,Interleukin 6 ,Innate immune system ,Cord factor ,biology ,business.industry ,Interleukin ,Middle Aged ,Flow Cytometry ,Interleukin 10 ,030104 developmental biology ,The Journal of Gerontology: Biological Sciences ,Immunology ,biology.protein ,Cytokines ,Female ,Geriatrics and Gerontology ,business ,030215 immunology - Abstract
Both aging and HIV infection are associated with an enhanced pro-inflammatory environment that contributes to impaired immune responses and is mediated in part by innate immune pattern-recognition receptors. MINCLE is a C-type lectin receptor that recognizes trehalose-6,6ʹ-dimycolate or “cord factor,” the most abundant glycolipid in Mycobacterium tuberculosis. Here, we evaluated MINCLE function in monocytes in a cohort of HIV-infected and uninfected young (21–35 years) and older adults (≥60 years) via stimulation of peripheral blood mononuclear cells with trehalose-6,6-dibehenate, a synthetic analog of trehalose-6,6ʹ-dimycolate and measurement of cytokine production (interleukin [IL]-10, IL-12, IL-6, tumor necrosis factor-α) by multicolor flow cytometry. Our studies show an age- and HIV-associated increase in cytokine multifunctionality of monocytes both at the population and single cell level that was dominated by IL-12, IL-10, and IL-6. These findings provide insight into the host response to M. tuberculosis and possible sources for the pro-inflammatory environment seen in aging and HIV infection.
- Published
- 2018
31. Mycobacterial cord factor enhances migration of neutrophil-like HL-60 cells by prolonging AKT phosphorylation
- Author
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Lark Kyun Kim, Ji Jing Yan, Seok Chung, Wook Bin Lee, and Ji Seon Kang
- Subjects
0301 basic medicine ,Chemokine ,Cord factor ,Kinase ,Immunology ,Chemotaxis ,Biology ,Microbiology ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Immune system ,Virology ,biology.protein ,Phosphorylation ,Secretion ,Protein kinase B ,030217 neurology & neurosurgery - Abstract
Trehalose 6,6'-dimycolate (TDM), or cord factor, is a crucial stimulus of immune responses during Mycobacterium tuberculosis infection. Although TDM has immuno-stimulatory properties, including adjuvant activity and the ability to induce granuloma formation, the mechanisms underlying these remain unknown. We hypothesized that TDM stimulates transendothelial migration of neutrophils, which are the first immune cells to infiltrate the tissue upon infection. In this study, it was shown that TDM enhances N-formylmethionyl-leucyl-phenylalanine (fMLP)-induced chemotaxis and transendothelial movement by prolonging AKT phosphorylation in human neutrophils. TDM induced expression of macrophage-inducible C-type lectin, a receptor for TDM, and induced secretion of pro-inflammatory cytokines and chemokines in differentiated HL-60 cells. In 2- and 3-D neutrophil migration assays, TDM-stimulated neutrophils showed increased fMLP-induced chemotaxis and transendothelial migration. Interestingly, following fMLP stimulation of TDM-activated neutrophils, AKT, a crucial kinase for neutrophil polarization and chemotaxis, showed prolonged phosphorylation at serine 473. Taken together, these data suggest that TDM modulates transendothelial migration of neutrophils upon mycobacterial infection through prolonged AKT phosphorylation. AKT may therefore be a promising therapeutic target for enhancing immune responses to mycobacterial infection.
- Published
- 2017
32. A mycobacteriophage-derived trehalose-6,6'-dimycolate-binding peptide containing both antimycobacterial and anti-inflammatory abilities.
- Author
-
Lin Wei, Jing Wu, Han Liu, Hailong Yang, Mingqiang Rong, Dongsheng Li, Pinghu Zhang, Junyou Han, and Ren Lai
- Subjects
- *
MYCOBACTERIA , *BACTERIOPHAGES , *MYCOBACTERIUM tuberculosis , *GLYCOLIPIDS , *IMMUNOPATHOLOGY , *ANTITUBERCULAR agents - Abstract
Bacteriophages, the viruses of eubacteria, have developed unique mechanisms to interact with their host bacteria. They have been viewed as potential antibacterial therapeutics. Mycobacteriophage-derived compounds may interact with Mycobacterium tuberculosis (MTB) and/or its components, such as the cord factor, trehalose-6,6'-dimycolate (TDM), which is the most abundant glycolipid produced on the surface of MTB. TDM emulsion injected intravenously into mice induces lung immunopathology that mimics many aspects of MTB infection. Thus, TDM is an important target for anti-MTB agent development. On the basis of genomics information of mycobacteriophages, 200 peptides were synthesized. Their effects on MTB, their interactions with TDM, and anti-inflammatory activities were tested. One of them (PK34) showed MTB-killing activity with a minimal inhibitory concentration of 50 (Jig/ml and TDM-binding ability. In a mouse model, PK34 showed comparable ability to clear MTB as rifampin did in vivo. It also exerted strong activity to inhibit MTB or TDM-induced inflammation in vivo. PK34 significantly inhibited inflammatory cytokines secretions by inactivating MAPK and PKB signals while it maintained certain proinflammatory cytokine production. It is possible to prospect for TDM-binding and/or anti-MTB peptides by mining the mycobacteriophages genome. In addition to its direct MTB-killing ability, PK34 might be a useful adjunct in the treatment of granulomatous inflammation occurring during myco-bacterial infection or a template for developing antituberculosis (TB) agents because of its immunoregulative effects. As a TDM-binding peptide, PK34 may be a promising tool to study TDM's interactions with corresponding receptors and signal pathways. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
33. Recognition of the mycobacterial cord factor by Mincle: relevance for granuloma formation and resistance to tuberculosis.
- Author
-
Lang, Roland
- Subjects
MYCOBACTERIUM tuberculosis ,MACROPHAGES ,GRANULOMA ,TREHALOSE-6-phosphate synthase ,LECTINS - Abstract
The world's most successful intracellular bacterial pathogen, Mycobacterium tuberculosis (MTB), survives inside macrophages by blocking phagosome maturation and establishes chronic infection characterized by the formation of granulomas. Trehalose-6,6-dimycolate (TDM), the mycobacterial cord factor, is the most abundant cell wall lipid of virulent mycobacteria, is sufficient to cause granuloma formation, and has long been known to be a major virulence factor of MTB. Recently, TDM has been shown to activate the Syk-Card9 signaling pathway in macrophages through binding to the C-type lectin receptor Mincle. The Mincle-Card9 pathway is required for activation of macrophages by TDM in vitro and for granuloma formation in vivo following injection of TDM. Whether this pathway is also exploited by MTB to reprogram the macrophage into a comfortable niche has not been explored yet. Several recent studies have investigated the phenotype of Mincle-deficient mice in mycobacterial infection, yielding divergent results in terms of a role for Mincle in host resistance. Here, we review these studies, discuss possible reasons for discrepant results and highlight open questions in the role of Mincle and other C-type lectin receptors in the infection biology of MTB. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
34. Structural Definition of Trehalose 6-Monomycolates and Trehalose 6,6'-Dimycolates from the Pathogen Rhodococcus equi by Multiple-Stage Linear Ion-Trap Mass Spectrometry with Electrospray Ionization.
- Author
-
Hsu, Fong-Fu, Wohlmann, Jens, Turk, John, and Haas, Albert
- Subjects
- *
RHODOCOCCUS equi , *TREHALOSE , *ELECTROSPRAY ionization mass spectrometry , *IONS , *BACTERIAL cell walls - Abstract
The cell wall of the pathogenic bacterium Rhodococcus equi ( R. equi) contains abundant trehalose monomycolate (TMM) and trehalose dimycolate (TDM), the glycolipids bearing mycolic acids. Here, we describe multiple-stage (MS) linear ion-trap (LIT) mass spectrometric approaches toward structural characterization of TMM and TDM desorbed as [M + Alk] (Alk = Na, Li) and as [M + X] (X = CHCO, HCO) ions by electrospray ionization (ESI). Upon MS ( n = 2, 3, 4) on the [M + Alk] or the [M + X] adduct ions of TMM and TDM, abundant structurally informative fragment ions are readily available, permitting fast assignment of the length of the meromycolate chain and of the α-branch on the mycolyl residues. In this way, structures of TMM and TDM isolated from pathogenic R. equi strain 103 can be determined. Our results indicate that the major TMM and TDM molecules possess 6, and/or 6'-mycolyl groups that consist of mainly C14 and C16 α-branches with meromycolate branches ranging from C18 to C28, similar to the structures of the unbound mycolic acids found in the cell envelope. Up to 60 isobaric isomers varying in chain length of the α-branch and of the meromycolate backbone were observed for some of the TDM species in the mixture. This mass spectrometric approach provides a direct method that affords identification of various TMM and TDM isomers in a mixture of which the complexity of this lipid class has not been previously reported using other analytical methods. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
35. The mycolyltransferase 85A, a putative drug target of Mycobacterium tuberculosis: Development of a novel assay and quantification of glycolipid-status of the mycobacterial cell wall
- Author
-
Elamin, Ayssar A., Stehr, Matthias, Oehlmann, Wulf, and Singh, Mahavir
- Subjects
- *
TRANSFERASES , *DRUG target , *MYCOBACTERIUM tuberculosis , *FIRE assay , *GLYCOLIPIDS , *MYCOBACTERIA , *BACTERIAL cell walls , *BACILLUS (Bacteria) - Abstract
Abstract: The enzymes of the antigen 85 complex (Ag85A, B, and C) possess mycolyltransferase activity and catalyze the synthesis of the most abundant glycolipid of the mycobacterial cell wall, the cord factor. The cord factor (trehalose 6,6′-dimycolate, TDM) is essential for the integrity of the mycobacterial cell wall and pathogenesis of the bacillus. Thus, TDM biosynthesis is regarded as a potential drug target for control of Mycobacterium tuberculosis infections. Trehalose 6,6′-dimycolate (TDM) is synthesized from two molecules of trehalose-6′-monomycolate (TMM) by antigen 85A. We report here a novel enzyme assay using the natural substrate TMM. The novel colorimetric assay is based on the quantification of glucose from the degradation of trehalose, which is the product from catalytic activity of antigen 85A. Using the new assay, K m and K cat were determined with values of 129.6±8.1µM and 65.4±4.1min−1, respectively. This novel assay is also suitable for robust high-throughput screening (HTS) for compound library screening against mycolyltransferase (antigen 85A). The assay is significantly faster and more convenient to use than all assays currently in use. The assay has a very low coefficient of variance (0.04) in 96-well plates and shows a Z′ factor of 0.67–0.73, indicating the robustness of the assay. In addition, this new assay is highly suitable for the quantification of total TMM of the mycobacterial cell envelope. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
36. Inhibitory effects of mycobacterial cell wall lipids on bovine lung surfactant extract: An in vitro study at the air–aqueous interface
- Author
-
Chimote, G. and Banerjee, R.
- Subjects
- *
CHEMICAL inhibitors , *BACTERIAL cell walls , *SURFACE active agents , *LIPOPROTEINS , *GAS-liquid interfaces , *PULMONARY alveoli , *BILAYER lipid membranes ,TUBERCULOSIS pathogenesis - Abstract
Abstract: Lung surfactant is a lipoprotein mixture synthesized by the type II alveolar cells in the lungs and lines the air–aqueous interface. It is essential for stabilizing the pulmonary alveoli. Deficiency or dysfunction of the surfactant due to chemicals or toxins results in alveolar collapse and if untreated leads to respiratory distress. In pulmonary tuberculosis, Mycobacterium tuberculosis bacteria reside in the alveoli, in close physical proximity with the alveolar surfactant. The surface active mycobacterial cell wall lipids may easily detach from bacterial cell wall and interact with surfactant components altering their surface activity. In this study, effects of mycolic acid and cord factor (the abundant surface lipids of mycobacterial cell wall) on the surface activity of modified bovine surfactant extract (Survanta™) were characterized in vitro using the Wilhelmy surface balance at physiological temperature (37°C) and pH 7.4. Inhibitory effects of mycobacterial cell wall lipids on the terminal airway surfactant were evaluated using a capillary surfactometer. Addition of graded amounts of mycolic acid and cord factor significantly increased the minimum surface tension of Survanta™ monolayer from <1mN/m to ∼11–20mN/m. Presence of mycobacterial cell wall lipids decreased the rate and magnitude of Survanta™ adsorption and fluidized the surfactant monolayer. Capillary surfactometer study exhibited 100% capillary closure on addition of mycobacterial cell wall lipids to the modified bovine surfactant extract. AFM imaging revealed alteration of surface topography and presence of aggregates on addition of mycobacterial cell wall lipids to Survanta™ monolayer. This study suggests a biophysical inhibition of lung surfactant which may play a role in the pathogenesis of pulmonary tuberculosis. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
37. Trehalose 6,6′-dimycolate on the surface of Mycobacterium tuberculosis modulates surface marker expression for antigen presentation and costimulation in murine macrophages
- Author
-
Kan-Sutton, Celestine, Jagannath, Chinnaswamy, and Hunter, Robert L.
- Subjects
- *
MYCOBACTERIUM tuberculosis , *MACROPHAGES , *CD antigens , *GENE expression , *T cells , *HYBRIDOMAS , *ANTIGENS , *LABORATORY mice , *BIOMARKERS - Abstract
Abstract: Trehalose 6,6′-dimycolate (TDM) is the most abundant lipid extracted from Mycobacterium tuberculosis (MTB). TDM promotes MTB survival by decreasing phagosomal acidification and phagolysosomal fusion in macrophages. Delipidation of MTB using petroleum ether removes TDM and decreases MTB survival within host cells. TDM reconstituted onto MTB restores its virulent wild-type characteristics. We investigated the role of TDM in regulating surface marker expression in MTB-infected macrophages. Macrophages were infected with wild-type, delipidated, and TDM-reconstituted MTB for 24h and measured for changes in surface marker expression. TDM on MTB was found to specifically target MHCII, CD1d, CD40, CD80 and CD86. Both wild-type and TDM-reconstituted MTB suppressed or induced no change in expression of these surface markers, whereas delipidated MTB increased expression of the same markers. MTB-infected macrophages were also overlaid with MHCII-restricted T cell hybridomas which recognize Antigen 85B. Macrophages infected by wild-type and TDM-reconstituted MTB did not present antigen as well as delipidated MTB-infected macrophages. The evidence shown furthers supports the notion that TDM present on MTB promotes its survival and persistence in host macrophages. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
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38. Molecular interactions of cord factor with dipalmitoylphosphatidylcholine monolayers: Implications for lung surfactant dysfunction in pulmonary tuberculosis
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Chimote, G. and Banerjee, R.
- Subjects
- *
SURFACE active agents , *TUBERCULOSIS , *PROPERTIES of matter , *SCANNING probe microscopy , *SURFACES (Technology) - Abstract
Abstract: Molecular interactions between mycobacterial cell wall lipid, cord factor (CF) and the abundant surfactant lipid, dipalmitoylphosphatidylcholine (DPPC) were investigated using Langmuir monolayers at physiological temperatures (37°C). Surface topography of the films was visualized by atomic force microscopy (AFM). Thermodynamic behavior of the mixed monolayers was evaluated by investigating the molecular area excess, excess Gibbs free energy of mixing and maximum compressibility modulus (SCMmax). Cord factor formed immiscible and thermodynamically unstable monolayers with DPPC. Monolayer presence of cord factor altered the physical state of DPPC monolayers from liquid condensed to liquid expanded with the lowering of SCMmax from 160 to 40mN/m, respectively. AFM imaging exhibited smooth homogenous surface topography of DPPC films which in the presence of cord factor was markedly altered with the appearance of aggregates and increased surface roughness. The results highlight the capacity of cord factor to disturb DPPC monolayer organization and structure. Interfacial presence of cord factor results in DPPC monolayer fluidization. Lung surfactant function is attributed to its ability to form well packed low compressibility films. Such molecular interactions suggest a dysfunction of lung surfactant in pulmonary tuberculosis due to surfactant monolayer fluidization. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
39. The genetics of cell wall biosynthesis in Mycobacterium tuberculosis.
- Author
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Goude, Renan and Parish, Tanya
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MYCOBACTERIUM tuberculosis ,PATHOGENICITY of enteroviruses ,BACTERIAL cell walls ,BIOSYNTHESIS ,GENETIC regulation - Abstract
Despite an available vaccine and effective antibiotics, Mycobacterium tuberculosis is still the causative agent of almost 2 million deaths every year. The cell wall of M. tuberculosis is composed of sugars and lipids of exotic structure, many of which contribute to its pathogenicity. The majority of the enzymes responsible for building this structure are essential. However, they share very little homology with well-characterized enzymes, which makes their identification in the genome difficult. Despite this, our knowledge of the structure of the cell wall of M. tuberculosis is fairly complete and an increasing number of genes have been identified that are involved in its biosynthesis. By contrast, data concerning regulation of the expression of these genes and control of the cell wall composition are restricted. This review summarizes current information on the genetics of cell wall biosynthesis in M. tuberculosis, incorporating available data on gene organization and regulation. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
40. The role of trehalose dimycolate (cord factor) on morphology of virulent M. tuberculosis in vitro.
- Author
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Hunter, Robert Lee, Venkataprasad, Nandagopal, and Olsen, Margaret R.
- Subjects
MYCOBACTERIAL diseases ,LUNG diseases ,TUBERCULOSIS ,COLONIES - Abstract
Summary: Setting: M. tuberculosis (MTB) lose virulence during prolonged culture on artificial media. This loss of virulence is associated with a change in colony morphology. Several studies suggested that trehalose 6,6′ dimycolate (TDM or cord factor), contributes to colony morphology. Objective: To investigate the role of TDM in colony morphology of MTB using clinical isolates selected to have colony morphology typical of virulent or attenuated organisms. Design: Use immunohistochemical and physical chemical methods to assess the presence and distribution of TDM in rapidly growing pellicles of MTB. Results: TDM forms an insoluble crystalline monolayer at the air–water interfaces that is more rigid than that formed by any other biologic amphiphile and is strong enough to support a spreading pellicle of MTB. The surface of young pellicles of the isolate with virulent morphology displayed the regular linear pattern characteristic of monolayers of TDM. TDM was also identified in the open spaces of pellicles of MTB by immunohistochemistry. MTB with morphology of attenuated organisms had neither of these properties. Conclusion: These data suggest that the characteristic morphology of colonies of virulent MTB is due to TDM released from the surface of the organisms. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
41. Mycobacterial sulfolipid shows a virulence by inhibiting cord factor induced granuloma formation and TNF-α release
- Author
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Okamoto, Yuko, Fujita, Yukiko, Naka, Takashi, Hirai, Manabu, Tomiyasu, Ikuko, and Yano, Ikuya
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- *
MYCOBACTERIAL diseases , *MACROPHAGES , *ANTIGEN presenting cells , *TUBERCULIN - Abstract
Abstract: Virulence mechanism of infection with Mycobacterium tuberculosis is currently focused to be clarified in the context of cell surface lipid molecule. Comparing two mycobacterial glycolipids, we observed toxicity and prominent granulomatogenic activity of trehalose 6,6′-dimycolate (TDM) injection in mice, evident by delayed body weight gain and histological observations, whereas 2,3,6,6′-tetraacyl trehalose 2′-sulfate (SL) was non-toxic and non-granulomatogenic. Likewise, TDM but not SL caused temporarily, but marked increase of lung indices, indicative of massive granuloma formation. Interestingly, co-administration of TDM and SL prevented these symptoms distinctively and SL inhibited TDM-induced release of tumor necrosis factor alpha (TNF-α) in a dose-dependent manner. Histological findings and organ index changes also showed marked inhibition of TDM induced granuloma formation by co-administration of SL. Simultaneous injection of SL together with TDM was highly effective for this protection, as neither injection 1h before nor after TDM injection showed highly inhibitory. In parallel studies on a cellular level, TDM elicited strong TNF-α release from alveolar but not from peritoneal macrophages in vitro. This effect was blocked when alveolar macrophages were incubated in wells simultaneously coated with TDM and SL, indicating that SL suppresses TDM-induced TNF-α release from macrophages. Our results suggest a novel mechanism by which SL could contribute to virulence at early stage of mycobacterial infection or stimulation with the glycolipids by counteracting the immunopotentiating effect of TDM. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
42. Macrophage scavenger receptor down-regulates mycobacterial cord factor-induced proinflammatory cytokine production by alveolar and hepatic macrophages
- Author
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Ozeki, Yuriko, Tsutsui, Hiroko, Kawada, Norifumi, Suzuki, Hiroshi, Kataoka, Motoyuki, Kodama, Tatsuhiko, Yano, Ikuya, Kaneda, Kenji, and Kobayashi, Kazuo
- Subjects
- *
MACROPHAGES , *TUMOR necrosis factors , *KUPFFER cells , *CYTOKINES - Abstract
Abstract: We aimed to reveal the regulatory function of macrophage scavenger receptor-A (MSR-A) in proinflammatory cytokine production by macrophages stimulated with mycobacterial cord factor (CF). By the culture with CF, MSR-A (+/+) alveolar macrophages and Kupffer cells produced TNF-α/MIP-1α in a time- and dose-dependent manner. However, the amounts of cytokines produced by them were much less compared to those produced by MSR-A (−/−) macrophages. Consistent with this, treatment of MSR-A (+/+) macrophages with anti-MSR-A antibody increased TNF-α production. Binding of CF to MSR-A was demonstrated by measuring the binding affinity. These results indicate that CF binds MSR-A, and MSR-A down-regulates TNF-α/MIP-1α production by activated macrophages, suggesting the role of this receptor in suppression of excessive inflammatory responses during mycobacterial infection. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
43. Intragranulomatous necrosis in lungs of mice infected by aerosol with Mycobacterium tuberculosis is related to bacterial load rather than to any one cytokine or T cell type
- Author
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Gil, Olga, Guirado, Evelyn, Gordillo, Sergi, Díaz, Jorge, Tapia, Gustavo, Vilaplana, Cristina, Ariza, Aurelio, Ausina, Vicenç, and Cardona, Pere-Joan
- Subjects
- *
NECROSIS , *TUBERCULOSIS , *MYCOBACTERIAL diseases , *CELLULAR immunity - Abstract
Abstract: Low dose aerosol infection of C57BL/6 mice with a clinical strain of Mycobacterium tuberculosis (UTE 0335 R) induced intragranulomatous necrosis in pulmonary granulomas (INPG) at week 9 postinfection. Infection of different knockout (KO) mouse strains with UTE 0335 R induced INPG in all strains and established two histopathological patterns. The first pattern was seen in SCID mice and in mice with deleted α/β T receptor, TNF R1, IL-12, IFN-γ, or iNOS genes, and showed a massive INPG with a high granulomatous infiltration of the lung, a large and homogeneous eosinophilic necrosis full of acid-fast bacilli, with marked karyorrhexis, coarse basophilic necrosis, and surrounded by patches delimited by partially conserved alveolar septum full of PMNs. The second pattern was seen in mice with deleted IL-1 R1, IL-6, IL-10, CD4, CD8 or γ/δ T cell receptor genes, and showed more discrete lesions with predominant homogeneous eosinophilic necrosis with few bacilli and surrounded by a well-defined lymphocyte-based ring. Local expression of IFN-γ, iNOS, TNF and RANTES showed no significant differences between these mouse strains generating a discrete INPG. Mouse strains showing a massive INPG showed higher, lower or equal expression values compared to the control strain. In conclusion, the severity of the INPG pattern correlated with pulmonary CFU counts, irrespective of the genetic absence or the infection-induced levels of cytokine mediators. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
44. Oral recombinant human or mouse lactoferrin reduces Mycobacterium tuberculosis TDM induced granulomatous lung pathology
- Author
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Jeffrey K. Actor, Shen-An Hwang, and Marian L. Kruzel
- Subjects
Lung Diseases ,0301 basic medicine ,medicine.medical_treatment ,Administration, Oral ,Heterologous ,Biology ,Biochemistry ,Article ,Microbiology ,Mycobacterium tuberculosis ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Immune system ,medicine ,Animals ,Humans ,Tuberculosis ,Molecular Biology ,Granuloma ,Cord factor ,Lactoferrin ,Macrophages ,Cell Biology ,biology.organism_classification ,medicine.disease ,Recombinant Proteins ,Mice, Inbred C57BL ,Trehalose dimycolate ,030104 developmental biology ,Cytokine ,chemistry ,Immunology ,biology.protein ,Cord Factors ,Cytokines ,Female ,030215 immunology - Abstract
Trehalose 6′6-dimycolate (TDM) is the most abundant glycolipid on the cell wall of Mycobacterium tuberculosis (MTB). TDM is capable of inducing granulomatous pathology in mouse models that resembles those induced by MTB infection. Using the acute TDM model, this work investigates the effect of recombinant human and mouse lactoferrin to reduce granulomatous pathology. C57BL/6 mice were injected intravenously with TDM at a dose of 25 μg·mouse−1. At day 4 and 6, recombinant human or mouse lactoferrin (1 mg·(100 μL)−1·mouse−1) were delivered by gavage. At day 7 after TDM injection, mice were evaluated for lung pathology, cytokine production, and leukocyte populations. Mice given human or mouse lactoferrin had reduced production of IL-12p40 in their lungs. Mouse lactoferrin increased IL-6 and KC (CXCL1) in lung tissue. Increased numbers of macrophages were observed in TDM-injected mice given human or mouse lactoferrin. Granulomatous pathology, composed of mainly migrated leukocytes, was visually reduced in mice that received human or mouse lactoferrin. Quantitation of granulomatous pathology demonstrated a significant decrease in mice given human or mouse lactoferrin compared with TDM control mice. This report is the first to directly compare the immune modulatory effects of both heterologous recombinant human and homologous mouse lactoferrin on the development of TDM-induced granulomas.
- Published
- 2017
45. Influence of the Washing Buffer Composition on the Sensitivity of an Enzyme-Linked Immunosorbent Assay Using Mycobacterial Glycolipids as Capture Antigens.
- Author
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Traunmüller, Friederike, Haslinger, Isabella, Lagler, Heimo, Graninger, Wolfgang, Zeitlinger, MarkusAlexander, and Abdulla Abdel Salam, Haider
- Subjects
- *
ENZYME-linked immunosorbent assay , *IMMUNOENZYME technique , *SOLID-phase analysis , *GLYCOLIPIDS , *GLYCOCONJUGATES , *ANTIGENS , *IMMUNITY - Abstract
Immunogenic glycolipids from the cell wall of Mycobacterium tuberculosis are potential capture antigens in enzyme-linked immunosorbent assays (ELISAs) for the serodiagnostis of tuberculosis. Typically, washing steps in ELISAs are performed with buffers containing a detergent. However, Tween-20, the most commonly added detergent, was reported to be able to remove the coating of certain glycolipid antigens from microtitre wells. In order to determine the influence of the washing buffer composition on the results, we measured serum immunoglobulin G (IgG) against three mycobacterial glycolipids by ELISA, conducting three separate experiments with three different buffers: Tris-buffered saline (TBS), TBS plus 0.02% Tween-20 (TBS-Tween), or TBS plus 0.3% bovine serum albumin (TBSBSA). The capture antigens applied were lipoarabinomannan with the basic arabinose-containing motif (AraLAM), the mannose-capped version of lipoarabinomannan (ManLAM), and trehalose-6,6′-dimycolate (cord factor). All ELISAs achieved acceptable specificities around 95%. The sensitivities, however, varied widely, depending upon the sort of washing buffer used. In 38 patients with sputum smear-positive pulmonary tuberculosis and control groups of 79 patients with non-tuberculosis lung disease and 92 healthy volunteers, the anticord factor ELISA achieved 100%, 31.6%, and 60.5% with TBS, TBS-Tween, and TBS-BSA, respectively. Corresponding sensitivity values for AraLAM were 39.5%, 26.3%, and 23.7%, and for ManLAM 94.7%, 65.8%, and 55.3%. We conclude that Tween-20 or BSA should be omitted from the washing buffer in ELISAs, when the capture antigen is of lipid nature. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
46. Possible antenatal and perinatal related factors in development of cystic periventricular leukomalacia
- Author
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Murata, Yasutaka, Itakura, Atsuo, Matsuzawa, Katsuji, Okumura, Akihisa, Wakai, Kenji, and Mizutani, Shigehiko
- Subjects
- *
BRAIN injuries , *NONSTEROIDAL anti-inflammatory agents , *INDOMETHACIN , *MAGNESIUM - Abstract
Cystic periventricular leukomalacia (cPVL), the principal ischemic brain injury in premature infants, is characterized by necrosis of the white matter in the periventricular region and the major neuropathology for spastic motor deficits in cerebral palsy or epilepsy. Recent reports strongly suggest that the brain injury associated with cPVL may have already occurred in utero. In this study we searched retrospectively for possible clinical situations related to cPVL to facilitate assessment of optimal management. A total of 201 babies born at gestational ages from 24 to 33 weeks were entered into the study (1992–1997) and examined for involvement of 18 factors in cPVL retrospectively. And psychomotor development was examined at least until 18 months of corrected age. Among 201 premature babies 35 cases were diagnosed as cPVL later developed spastic diplegia. There are 23 cases of preeclampsia, no infant suffering from cPVL. In the univariate analysis, exposure to antenatal indomethacin, cord length ≥40 cm, and a low Apgar score were significantly associated with a 2–3 risk increased of cPVL occurrence, while antenatal magnesium sulfate reduced the risk. Chorioamnionitis was positively correlated with the risk, but did not reach statistical significance. In the multivariate analysis we found the statistical significance in exposure to antenatal indomethacin, a low Apgar score, and antenatal magnesium sulfate. Our results suggested that preeclampsia and antenatal exposure of magnesium sulfate reduced the risk while antenatal exposure of indomethacin and low Apgar score associated with the occurrence of cPVL. These findings support a growing consensus that cPVL is often the result of maternal and fetal factors as well as antenatal treatment. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
47. 6,6′-Dimycoloyl trehalose from a rapidly growing Mycobacterium: an alternative antigen for tuberculosis serodiagnosis
- Author
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López-Marín, Luz M., Segura, Erika, Hermida-Escobedo, Carlos, Lemassu, Anne, and César Salinas-Carmona, Mario
- Subjects
- *
MYCOBACTERIUM , *TUBERCULOSIS diagnosis - Abstract
Mycobacterial O-acyltrehaloses have been described as highly specific and sensitive reagents for tuberculosis immunodiagnosis. An O-acyltrehalose-containing lipid fraction from the rapidly growing Mycobacterium fortuitum was found to include additional antigens, which presented high cross-reactivity with sera from tuberculosis-infected patients. Based on a combination of selective chemical degradations, thin-layer-chromatography analyses and 1H-nuclear magnetic resonance spectroscopy, the antigenic by-product was identified as 6,6′-dimycoloyl trehalose, the so-called cord factor. The lipid was purified and tested in ELISA for pulmonary tuberculosis serodiagnosis. Sensitivity and specificity of the test were found to be 66.6–74.1% and 95.2–99.0%, respectively, showing a slightly higher efficiency as compared to the ELISA performed using 6,6′-dimycoloyl trehalose from Mycobacterium tuberculosis. No cross-reactivity was found with sera from Nocardia-infected individuals. [Copyright &y& Elsevier]
- Published
- 2003
- Full Text
- View/download PDF
48. Cord factor as an invisibility cloak? A hypothesis for asymptomatic TB persistence
- Author
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Jeffrey K. Actor, Shen-An Hwang, Chinnaswamy Jagannath, and Robert L. Hunter
- Subjects
0301 basic medicine ,Microbiology (medical) ,Cell type ,030106 microbiology ,Immunology ,Inflammation ,Biology ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Immune system ,medicine ,Animals ,Humans ,Tuberculosis ,Macrophage ,Lectins, C-Type ,Receptors, Immunologic ,Receptor ,Cord factor ,Macrophages ,Water ,Mycobacterium tuberculosis ,Trehalose ,Cell biology ,030104 developmental biology ,Infectious Diseases ,chemistry ,Asymptomatic Diseases ,Cord Factors ,medicine.symptom ,Signal transduction ,Signal Transduction - Abstract
Mycobacterium tuberculosis (MTB) has long been known to persist in grossly normal tissues even in people with active lesions and granulomas in other parts of the body. We recently reported that post-primary TB begins as an asymptomatic infection that slowly progresses, accumulating materials for a massive necrotizing reaction that results in cavitation. This paper explores the possible roles of trehalose 6,6' dimycolate (TDM) or cord factor in the ability of MTB to persist in such lesions without producing inflammation. TDM is unique in that it has three distinct sets of biologic activities depending on its physical conformation. As a single molecule, TDM stimulates macrophage C-type lectin receptors including Mincle. TDM can also form three crystal like structures, cylindrical micelles, intercalated bilayer and monolayer, that have distinct non receptor driven activities that depend on modulation of interactions with water. In the monolayer form, TDM is highly toxic and destroys cells in minutes upon contact. The cylindrical micelles and an intercalated bilayer have surfaces composed entirely of trehalose which protect MTB from killing in macrophages. Here we review evidence that these trehalose surfaces bind water. We speculate that this immobilized water constituites of an "invisibility cloak" that facilitates the persistence of MTB in multiple cell types without producing inflammation, even in highly immune individuals.
- Published
- 2016
49. Inflammatory Properties and Adjuvant Potential of Synthetic Glycolipids Homologous to Mycolate Esters of the Cell Wall of Mycobacterium tuberculosis
- Author
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Hermann Giresse Tima, Mohaned M. Sahb, Georges Potemberg, Olivier Denis, Mohsin O. Mohammed, Jacques Piette, Klarah Sherzad Baols, Laurent L'Homme, Mark S. Baird, Marta Romano, Pauline Lehebel, Roland Lang, Juma'a R. Al Dulayymi, Sylvie Legrand, Kris Huygen, and Rudi Beyaert
- Subjects
0301 basic medicine ,Arabinose ,Innate immune system ,Cord factor ,Mutant ,Inflammasome ,Biology ,Trehalose ,3. Good health ,Microbiology ,Trehalose dimycolate ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Glycolipid ,Biochemistry ,chemistry ,medicine ,Immunology and Allergy ,medicine.drug - Abstract
The cell wall of mycobacteria is characterised by glycolipids composed of different classes of mycolic acids (MAs; alpha-, keto-, and methoxy-) and sugars (trehalose, glucose, and arabinose). Studies using mutant Mtb strains have shown that the structure of MAs influences the inflammatory potential of these glycolipids. As mutant Mtb strains possess a complex mixture of glycolipids, we analysed the inflammatory potential of single classes of mycolate esters of the Mtb cell wall using 38 different synthetic analogues. Our results show that synthetic trehalose dimycolate (TDM) and trehalose, glucose, and arabinose monomycolates (TMM, GMM, and AraMM) activate bone marrow-derived dendritic cells in terms of the production of pro-inflammatory cytokines (IL-6 and TNF-α) and reactive oxygen species, upregulation of costimulatory molecules, and activation of NLRP3 inflammasome by a mechanism dependent on Mincle. These findings demonstrate that Mincle receptor can also recognise pentose esters and seem to contradict the hypothesis that production of GMM is an escape mechanism used by pathogenic mycobacteria to avoid recognition by the innate immune system. Finally, our experiments indicate that TMM and GMM, as well as TDM, can promote Th1 and Th17 responses in mice in an OVA immunisation model, and that further analysis of their potential as novel adjuvants for subunit vaccines is warranted.
- Published
- 2016
50. Importance of Cell Wall-Associated Poly-α-L-Glutamine in the Biology of Pathogenic Mycobacteria
- Author
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Harish Chandra, Nirupama Banerjee, Rajni Garg, Rajesh Mani, Manish Gupta, Deeksha Tripathi, and Rakesh Bhatnagar
- Subjects
Mycobacterium tuberculosis ,Cell wall ,Glutamine ,medicine.anatomical_structure ,Cord factor ,biology ,Antigen ,Glutamine synthetase ,Cell ,medicine ,biology.organism_classification ,Pathogen ,Microbiology - Abstract
Mycobacterium tuberculosis (Mtb), the formidable scourge known to mankind since ancient times, has remained untamed despite vigorous scientific research in the field. In the last several decades, significant advances have been made to study this pathogen; however, a lot more remains in the realm of unknown. The complex and unique cell wall of the bacterium is a major factor contributing to the unrestrained success of the pathogen in infecting millions around the world. Since the discovery of this bacterium, numerous studies have attempted to unravel the complexities of mycobacterial cell envelop to characterize individual constituents and their importance in pathobiology of Mtb. Major components of the cell envelop of mycobacteria such as lipid-linked polysaccharides-lipoarabinomannan (LAM), dimycolyl trehalose (cord factor), sulfolipids, and mycolyl-arabinogalactan-peptidoglycan (mAGP) complex have been investigated extensively. However, a lesser known molecule, poly-α-l-glutamine/glutamate (PLG), that constitutes ~10% of dry weight of cell wall has not attracted as much attention. As early as 1990, Hirschfield et al. isolated PLG as insoluble material and showed its association with the Mtb cell wall. In the last few years, our group has been working to identify enzymes that may play a role in the synthesis/assembly and localization of this polymer in the cell wall of mycobacteria. Our recently published work has shown that PLG by itself is weakly immunogenic in mice, but when combined with protein antigens, it can stimulate different arms of the T helper-mediated responses, demonstrating its potential to act as an adjuvant (Mani et al. 2018).
- Published
- 2019
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