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9 results on '"Olivier Mesdjian"'

1. Microtubules restrict F-actin polymerization to the immune synapse via GEF-H1 to maintain polarity in lymphocytes

Author

Judith Pineau, Léa Pinon, Olivier Mesdjian, Jacques Fattaccioli, Ana-Maria Lennon Duménil, and Paolo Pierobon

Subjects
B lymphocytes, immune synapse, cytoskeleton, cell polarity, GEF-H1, Medicine, Science, Biology (General), QH301-705.5
Abstract

Immune synapse formation is a key step for lymphocyte activation. In B lymphocytes, the immune synapse controls the production of high-affinity antibodies, thereby defining the efficiency of humoral immune responses. While the key roles played by both the actin and microtubule cytoskeletons in the formation and function of the immune synapse have become increasingly clear, how the different events involved in synapse formation are coordinated in space and time by actin–microtubule interactions is not understood. Using a microfluidic pairing device, we studied with unprecedented resolution the dynamics of the various events leading to immune synapse formation and maintenance in murine B cells. Our results identify two groups of events, local and global, dominated by actin and microtubules dynamics, respectively. They further highlight an unexpected role for microtubules and the GEF-H1-RhoA axis in restricting F-actin polymerization at the lymphocyte–antigen contact site, thereby allowing the formation and maintenance of a unique competent immune synapse.

Published
2022
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3. Phenotyping polarization dynamics of immune cells using a lipid droplet-cell pairing microfluidic platform

Author

Léa Pinon, Nicolas Ruyssen, Judith Pineau, Olivier Mesdjian, Damien Cuvelier, Anna Chipont, Rachele Allena, Coralie L. Guerin, Sophie Asnacios, Atef Asnacios, Paolo Pierobon, and Jacques Fattaccioli

Subjects
Genetics, Radiology, Nuclear Medicine and imaging, Biochemistry, Genetics and Molecular Biology (miscellaneous), Biochemistry, Computer Science Applications, Biotechnology
Abstract

The immune synapse is the tight contact zone between a lymphocyte and a cell presenting its cognate antigen. This structure serves as a signaling platform and entails a polarization of intracellular components necessary to the immunological function of the cell. While the surface properties of the presenting cell are known to control the formation of the synapse, their impact on polarization has not yet been studied. Using functional lipid droplets as tunable artificial presenting cells combined with a microfluidic pairing device, we simultaneously observe synchronized synapses and dynamically quantify polarization patterns of individual B cells. By assessing how ligand concentration, surface fluidity, and substrate rigidity impact lysosome polarization, we show that its onset and kinetics depend on the local antigen concentration at the synapse and on substrate rigidity. Our experimental system enables a fine phenotyping of monoclonal cell populations based on their synaptic readout.

Published
2022

4. Phenotyping Polarization Dynamics Of Immune Cells Using A Lipid Droplet - Cell Pairing Microfluidic Platform

Author

Léa Pinon, Nicolas Ruyssen, Judith Pineau, Olivier Mesdjian, Damien Cuvelier, Anna Chipont, Rachele Allena, Coralie L. Guerin, Sophie Asnacios, Atef Asnacios, Paolo Pierobon, Jacques Fattaccioli, Institut de Biomécanique Humaine Georges Charpak (IBHGC), Université Sorbonne Paris Nord-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), Institut Curie [Paris], Physico-Chimie-Curie (PCC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut Curie [Paris]-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Paris-Centre de Recherche Cardiovasculaire (PARCC - UMR-S U970), Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire de biomécanique (LBM), Université Paris 13 (UP13)-Université Sorbonne Paris Cité (USPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Sorbonne Université - Faculté de Physique (UFR 925), Sorbonne Université (SU), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Immunité et cancer (U932), Université Paris Descartes - Paris 5 (UPD5)-Institut Curie [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM), Physicochimie des Electrolytes, Colloïdes et Sciences Analytiques (PECSA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Colloïdes et Matériaux Divisés (LCMD), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]
Abstract

The immune synapse is the tight contact zone between a lymphocyte and a cell presenting its cognate antigen. This structure serves as a signaling platform and entails a polarization of intra-cellular components, necessary to the immunological function of the cell. While the surface properties of the presenting cell are known to control the formation of the synapse, their impact on polarization has not yet been studied.Using functional lipid droplets as tunable artificial presenting cells combined with a microfluidic pairing device, we simultaneously observe synchronized synapses and dynamically quantify polarization patterns of individual B cells. By assessing how ligand concentration, surface fluidity and substrate rigidity impact lysosome polarization, we show that its onset and kinetics depend on the local antigen concentration at the synapse and on substrate rigidity. Our experimental system enables a fine phenotyping of monoclonal cell populations based on their synaptic readout.

Published
2021
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5. Longitudinal to transverse metachronal wave transitions in an in-vitro model of ciliated bronchial epithelium

Author

Olivier Mesdjian, Chenglei Wang, Simon Gsell, Umberto D’Ortona, Julien Favier, Annie Viallat, Etienne Loiseau, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and ANR-16-CONV-0001,CENTURI,CenTuri : Centre Turing des Systèmes vivants(2016)

Subjects
Mucus, [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], General Physics and Astronomy, Humans, Bronchi, Cilia, respiratory system, Epithelium
Abstract

Myriads of cilia beat on ciliated epithelia, which are ubiquitous in life. When ciliary beats are synchronized, metachronal waves emerge, whose direction of propagation depends on the living system in an unexplained way. We show on a reconstructed human bronchial epithelium in-vitro that the direction of propagation is determined by the ability of mucus to be transported at the epithelial surface. Numerical simulations show that longitudinal waves maximise the transport of mucus while transverse waves, observed when the mucus is rigid and still, minimize the energy dissipated by the cilia.

Published
2021
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6. Enhancing the capture efficiency and homogeneity of single-layer flow-through trapping microfluidic devices using oblique hydrodynamic streams

Author

Marie-Caroline Jullien, Olivier Mesdjian, Rachele Allena, Jacques Fattaccioli, Nicolas Ruyssen, Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Pierre-Gilles de Gennes pour la Microfluidique, Institut de Biomécanique Humaine Georges Charpak (IBHGC), Université Sorbonne Paris Nord-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Institut Pierre-Gilles de Gennes [ANR-10-LABX-31, ANR-10-IDEX-0001-02, ANR-10-EQPX-34], Agence Nationale de la Recherche (ANR Jeune Chercheur PHAGODROP) French National Research Agency (ANR) [ANR-15-CE18-0014-01], Ecole Doctorale ED 388 (Chimie Paris Centre), Ecole Normale Superieure de Rennes (ENS Rennes, Contrat Doctoral Specifique Normalien), ANR-10-LABX-0031,IPGG_LABEX,Pierre-Gilles de Gennes Institute for microfluidics(2010), ANR-10-IDEX-0001,PSL,Paris Sciences et Lettres(2010), ANR-10-EQPX-0034,IPGG,Institut Pierre Gilles de Gennes pour la microfluidique(2010), ANR-15-CE18-0014,PhagoDrop,Phagocytose de gouttes d'émulsions fonctionnalisées par des IgG(2015), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), HESAM Université (HESAM)-HESAM Université (HESAM), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Fabrication, Materials science, Flow (psychology), Microfluidics, FOS: Physical sciences, Trapping, Photoresist, 01 natural sciences, 03 medical and health sciences, Materials Chemistry, 030304 developmental biology, [PHYS]Physics [physics], 0303 health sciences, business.industry, Orientation (computer vision), Homogeneity (statistics), 010401 analytical chemistry, Fluid Dynamics (physics.flu-dyn), Physics - Fluid Dynamics, Condensed Matter Physics, Chip, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Particles, Optoelectronics, business, Simulation
Abstract

With the aim to parallelize and monitor biological or biochemical phenomena, trapping and immobilization of objects such as particles, droplets or cells in microfluidic devices has been an intense area of research and engineering so far. Either being passive or active, these microfluidic devices are usually composed of arrays of elementary traps with various levels of sophistication. For a given array, it is important to have an efficient and fast immobilization of the highest number of objects, while optimizing the spatial homogeneity of the trapping over the whole chip. For passive devices, this has been achieved with two-layers structures, making the fabrication process more complex. In this work, we designed small microfluidic traps by single-layer direct laser writing into a photoresist, and we show that even in this simplest case, the orientation of the main flow of particles with respect to the traps have a drastic effect on the trapping efficiency and homogeneity. To better understand this phenomenon, we have considered two different flow geometries: parallel and oblique with respect to the traps array, and compared quantitatively the immobilization of particles with various sizes and densities. Using image analysis, we show that diagonal flows gives a spatial distribution of the trap loading that is more homogeneous over the whole chip as compared to the straight ones, and by performing FEM and trapping simulation, we propose a qualitative explanation of this phenomenon., Post-reviewing revised version

Published
2021
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8. Kinetically Enhanced Fabrication of Homogeneous Biomimetic and Functional Emulsion Droplets

Author

Lorraine Montel, A Michel, Léa Pinon, Christine Ménager, Olivier Mesdjian, Jacques Fattaccioli, and M Bernard

Subjects
Streptavidin, Biocompatibility, Population, Dispersity, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Electrochemistry, General Materials Science, education, Spectroscopy, education.field_of_study, technology, industry, and agriculture, Aqueous two-phase system, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, chemistry, Chemical engineering, Polar, Surface modification, lipids (amino acids, peptides, and proteins), Titration, 0210 nano-technology
Abstract

Characterized by a fluid and deformable interface, ligand-functionalized emulsion droplets are used as model probes to address biophysical, biological, and developmental questions. Functionalization protocols usually rely on the use of headgroup-modified phospholipids that are dissolved in the oil phase prior to emulsification, leading to a broad range of surface densities within a given droplet population. With the aim to coat particles homogeneously with biologically relevant lipids and proteins (streptavidin, immunoglobulins, etc.), we developed a reliable surface decoration protocol based on the use of polar cosolvents to dissolve the lipids in the aqueous phase after the droplet production. We show that the surface density of the lipids at the interface has a narrow normal distribution for droplets having the same size. We performed titration isotherms for lipids and biologically relevant proteins on these drops. Then, we studied the influence of the presence of surfactants in the medium on lipid insertion and compared the results for a range of polar cosolvents of increasing polarity. To assess both the generality and the biocompatibility of the method, we show that we can produce more sophisticated, monodisperse functional magnetic emulsions with a very high surface homogeneity. Using an oil denser than the surrounding culture medium, we show that IgG-coated droplets can be used as probes for phagocytosis experiments.

Published
2018

9. Luminescent and absorptive metal-coated emulsions for micro-velocimetry

Author

Yong Chen, Jacques Fattaccioli, Olivier Mesdjian, Département de Chimie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) (PASTEUR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Département de Chimie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Polydopamine, Materials science, Microfluidics, Analytical chemistry, FOS: Physical sciences, Particle, 02 engineering and technology, engineering.material, Condensed Matter - Soft Condensed Matter, 01 natural sciences, 010305 fluids & plasmas, chemistry.chemical_compound, Coating, Physics - Chemical Physics, 0103 physical sciences, Electrical and Electronic Engineering, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Chemical Physics (physics.chem-ph), Core-shell, Aqueous solution, Microchannel, Emulsion, Fluid Dynamics (physics.flu-dyn), Velocimetry, Physics - Fluid Dynamics, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, Chemical engineering, Oil droplet, engineering, Soft Condensed Matter (cond-mat.soft), Polystyrene, 0210 nano-technology, Layer (electronics)
Abstract

Fluorescent latex beads have been widely used as tracers in microfluidics over for the last decades. They have the advantages to be density matched with water and to be easily localizable using fluorescence microscopy. We have recently synthesized silver-coated oil droplets that are both luminescent and absorptive, by first coating the oil interface with a polydopamine layer and then depositing a silver layer by a redox process. They have a mean diameter of 6 \mu m and a their density has been matched to the density of water by adjusting the thickness of the metallic layer. In this work we used these particles as tracers to measure the velocity profile of a water flow in a PDMS microchannel with a rectangular cross-section, which allowed us to confirm the predictions of the Stokes equation with results comparable to those of common submicronic polystyrene particles., Comment: 19 pages

Published
2016
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