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12 results on '"Microscopie ultrastructurale - Ultrapole (CITECH)"'

1. HIV-1 hijacks the cell extracellular matrix to spread collectively and efficiently between T lymphocytes

Author

Frédéric Tangy, Faroudy Boufassa, Alexandre Dufour, Jean-Christophe Olivo-Marin, M. Mesel-Lemoine, Gianfranco Pancino, Adeline Mallet, Asier Sáez-Cirión, M.-I. Thoulouze, A. Desrames, Annie David, Olivier Lambotte, Félix A. Rey, M. Caillet, P. Bomme, Hugo Mouquet, C. Inizan, K. Bourdic, Thibault Lagache, Virologie Structurale - Structural Virology, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Sorbonne Université (SU), Dengue et Arbovirose (URE-DA), Institut Pasteur de Nouvelle-Calédonie, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Biologie Intégrée du Globule Rouge (BIGR (UMR_S_1134 / U1134)), Institut National de la Transfusion Sanguine [Paris] (INTS)-Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pointe-à-Pitre/Abymes [Guadeloupe] -Université des Antilles (UA)-Université Paris Cité (UPCité), HIV, Inflammation et persistance - HIV, Inflammation and Persistence, Institut Pasteur [Paris] (IP)-Université Paris Cité (UPCité), Microscopie ultrastructurale - Ultrapole (CITECH), Institut Pasteur [Paris] (IP), AP-HP Hôpital Bicêtre (Le Kremlin-Bicêtre), Immunologie des Maladies Virales et Autoimmunes (IMVA - U1184), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de recherche en épidémiologie et santé des populations (CESP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Paul Brousse-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Saclay, Génomique virale et vaccination, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Régulation des Infections Rétrovirales, Réponse humorale aux pathogènes, Analyse d'images biologiques - Biological Image Analysis (BIA), Columbia University [New York], This work was funded by grants from l’AgenceNationale de Recherche sur le SIDA et les hépatites (ANRS), l’Institut Pasteur (PTR-445), as well asby institutional grants from Institut Pasteur and the Centre National de la Recherche Scientifique(CNRS). CI was supported by an Allocation de Recherche du Ministère de l'Education Nationale, de laRecherche et de la Technologie and by a bourse from the Fondation pour la Recherche Médicale. MCwas supported by a fellowship from AXA Research fund, AD by a fellowship from l’Institut Pasteur(PTR-445), and TL by a Roux Fellowship (Institut Pasteur). We gratefully acknowledge the financialsupport of the FranceBioImaging infrastructure network supported by the French National ResearchAgency (ANR-10–INSB–04, Investments for the future and ANR-10-LABX-62-IBEID) and theRégion Ile-de-France (program DIM-Malinf). The support of E. Mottez (Center for HumanImmunology, Institut Pasteur) and A.M. Rey-Cuillé (ANRS) is thankfully acknowledged., ANR-10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010), and ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010)

Subjects
Infectivity, biology, Cell-Extracellular Matrix, [SDV]Life Sciences [q-bio], Cell, Human immunodeficiency virus (HIV), [SDV.BC]Life Sciences [q-bio]/Cellular Biology, medicine.disease_cause, Cell biology, Extracellular matrix, medicine.anatomical_structure, In vivo, [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology, medicine, biology.protein, Viral spread, Antibody
Abstract

Collective transmission via structures containing several virions has recently emerged as a highly efficient mode of viral spread. Here, we demonstrate that HIV-1 spreads between T lymphocytes in the form of viral particles colonies that are concentrated and sheltered in an extracellular matrix (ECM) lattice enabling their collective transmission upon cell contacts. Intrinsically, ECM-clustered viruses infect T lymphocytes more efficiently than individual viral particles. They preserve HIV-1 transmission from antiretroviral treatment (ArT) and potent broadly neutralizing antibodies. We also show that collagen induced by HIV-1 infection controls the clustering of virions and their collective spread, thereby enhancing infectivity. CD4+ T cells from HIV-1-infected patients produce and transmit ECM-virus clusters, supporting that they could be involved in vivo. This study provides new insights into modes of HIV-1 transmission and identifies a novel fundamental role for collagen in this process. HIV-1 spread via ECM-virus clusters may have important implications for viral dissemination and persistence, including during therapy.

Published
2021

2. Innate Immune Signals Induce Anterograde Endosome Transport Promoting MHC Class I Cross-Presentation

Author

Beaune, Gregory, Blanch-Mercader, Carles, Douezan, Stephane, Dumond, Julien, Gonzalez-Rodriguez, David, Cuvelier, Damien, Ondarçuhu, Thierry, Sens, Pierre, Dufour, Sylvie, Murrell, Michael, Charles-Orszag, Arthur, Tsai, Feng-Ching, Bonazzi, Daria, Manriquez, Valeria, Sachse, Martin, Mallet, Adeline, Salles, Audrey, Melican, Keira, Staneva, Ralitza, Bertin, Aurélie, Millien, Corinne, Goussard, Sylvie, Lafaye, Pierre, Shorte, Spencer, Piel, Matthieu, Krijnse-Locker, Jacomine, Brochard-Wyart, Françoise, Bassereau, Patricia, Duménil, Guillaume, Weimershaus, Mirjana, Mauvais, Francois-Xavier, Saveanu, Loredana, Adiko, Cézaire, Babdor, Joel, Abramova, Anastasia, Montealegre, Sebastian, Lawand, Myriam, Evnouchidou, Irini, Huber, Katharina Julia, Chadt, Alexandra, Zwick, Markus, Vargas, Pablo, Dussiot, Michaël, Lennon-Dumenil, Ana Maria, Brocker, Thomas, Al-Hasani, Hadi, Van Endert, Peter, National Institute for Materials Science (NIMS), Physico-Chimie-Curie (PCC), Institut Curie-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut Curie-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Paris-Centre de Recherche Cardiovasculaire (PARCC - UMR-S U970), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Institut Jacques Monod (IJM (UMR_7592)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Pathogénèse des Infections vasculaires, Institut Pasteur [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM), Microscopie ultrastructurale (plate-forme), Institut Pasteur [Paris], Imagopole (CITECH), Centre d'Immunologie de Marseille - Luminy (CIML), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Department of Neuroscience, Karolinska Institutet [Stockholm], Institut Curie, SAFT [Bordeaux], Société des accumulateurs fixes et de traction (SAFT), Ingénierie des Anticorps (plate-forme) - Antibody Engineering (Platform), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Compartimentation et dynamique cellulaires (CDC), Microscopie ultrastructurale - Ultrapole (CITECH), Diabète de Type 1 : mécanismes et traitements immunologiques, Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Necker Enfants-Malades (INEM - UM 111 (UMR 8253 / U1151)), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche sur l'Inflammation (CRI (UMR_S_1149 / ERL_8252 / U1149)), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche des Cordeliers (CRC), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Immunité et cancer, Institut Curie-Institut National de la Santé et de la Recherche Médicale (INSERM), Hémostase, bio-ingénierie et remodelage cardiovasculaires (LBPC), Université Paris 13 (UP13)-Université Paris Diderot - Paris 7 (UPD7)-Institut Galilée-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Curie [Paris], Université Paris Diderot - Paris 7 (UPD7)-Université Paris 13 (UP13)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Galilée, and Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0301 basic medicine, Male, Endosome, Antigen presentation, Fc receptor, Kinesins, Endosomes, Receptors, Fc, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Microtubules, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, Mice, Cross-Priming, Phagosomes, Animals, lcsh:QH301-705.5, Cells, Cultured, ComputingMilieux_MISCELLANEOUS, Phagosome, Innate immune system, biology, Chemistry, Histocompatibility Antigens Class I, Cross-presentation, Dendritic cell, Immunity, Innate, Cell biology, Toll-Like Receptor 4, Protein Transport, 030104 developmental biology, lcsh:Biology (General), rab GTP-Binding Proteins, biology.protein, Kinesin, Female
Abstract

Summary: Both cross-presentation of antigens by dendritic cells, a key pathway triggering T cell immunity and immune tolerance, and survival of several pathogens residing in intracellular vacuoles are intimately linked to delayed maturation of vesicles containing internalized antigens and microbes. However, how early endosome or phagosome identity is maintained is incompletely understood. We show that Toll-like receptor 4 (TLR4) and Fc receptor ligation induces interaction of the GTPase Rab14 with the kinesin KIF16b mediating plus-end-directed microtubule transport of endosomes. As a result, Rab14 recruitment to phagosomes delays their maturation and killing of an internalized pathogen. Enhancing anterograde transport by overexpressing Rab14, promoting the GTP-bound Rab14 state, or inhibiting retrograde transport upregulates cross-presentation. Conversely, reducing Rab14 expression, destabilizing Rab14 endosomes, and inhibiting anterograde microtubule transport by Kif16b knockdown compromise cross-presentation. Therefore, regulation of early endosome trafficking by innate immune signals is a critical parameter in cross-presentation by dendritic cells. : Weimershaus et al. identify a molecular complex that controls the intracellular trafficking along microtubules of antigens internalized by dendritic cells. They show that this trafficking is regulated by innate immune signals and regulates presentation of internalized antigens to T lymphocytes. Keywords: antigen presentation, cross-presentation, dendritic cell, MHC class I, endosome, small GTPase, kinesin, Rab14

Published
2018
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3. Evolutionary diversification of the HAP2 membrane insertion motifs to drive gamete fusion across eukaryotes

Author

Thomas Krey, Ahmed Haouz, Mark A. Johnson, Félix A. Rey, Juliette Fedry, Gérard Pehau-Arnaudet, Pierre Legrand, Jennifer Forcina, Virologie Structurale - Structural Virology, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Université Paris Descartes - Paris 5 (UPD5), Hannover Medical School [Hannover] (MHH), Brown University, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Microscopie ultrastructurale - Ultrapole (CITECH), Institut Pasteur [Paris] (IP), Protéopole, German Center for Infection Research - partner site Hannover-Braunschweig (DZIF), ERC Advanced grant CelCelFus (grant number 340371) received by FAR. Recurrent funding from the CNRS received by FAR. Recurrent funding from the Institut Pasteur received by FAR. Allocation ministerielle pour l’Ecole Polytechnique AMX received by JFe. National Science Foundation (NSF) (grant number IOS-1353798). Received by MJ. National Science Foundation (NSF) (grant number IOS-1540019). Received by MJ. National Institutes of Health Training Grant (grant number #T32-GM007601). Received by JFo., and European Project: 340371,EC:FP7:ERC,ERC-2013-ADG,CELCELFUS(2014)

Subjects
Protein Structure Comparison, 0301 basic medicine, MESH: Sequence Homology, Amino Acid, [SDV]Life Sciences [q-bio], Cell Membranes, Arabidopsis, Chlamydomonas reinhardtii, MESH: Chlamydomonas, Membrane Fusion, Biochemistry, Macromolecular Structure Analysis, MESH: Arabidopsis, MESH: Genetic Variation, Biology (General), Flowering Plants, Fusion, General Neuroscience, Eukaryota, Plants, Biological Evolution, Transmembrane protein, Cell biology, MESH: Eukaryota, Experimental Organism Systems, Cellular Structures and Organelles, General Agricultural and Biological Sciences, Research Article, Protein Structure, QH301-705.5, Arabidopsis Thaliana, MESH: Biological Evolution, MESH: Carrier Proteins, Brassica, MESH: Arabidopsis Proteins, Viral Structure, Biology, Research and Analysis Methods, MESH: Membrane Fusion, Microbiology, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, Model Organisms, Plant and Algal Models, Virology, Vesicles, Molecular Biology, Sequence Homology, Amino Acid, General Immunology and Microbiology, Arabidopsis Proteins, Chlamydomonas, Organisms, Biology and Life Sciences, Membrane Proteins, Proteins, Genetic Variation, Lipid bilayer fusion, Cell Biology, biology.organism_classification, Fusion protein, MESH: Germ Cells, Germ Cells, 030104 developmental biology, Membrane protein, Liposomes, Helix, Carrier Proteins
Abstract

HAPLESS2 (HAP2) is a broadly conserved, gamete-expressed transmembrane protein that was shown recently to be structurally homologous to viral class II fusion proteins, which initiate fusion with host cells via insertion of fusion loops into the host membrane. However, the functional conformation of the HAP2 fusion loops has remained unknown, as the reported X-ray structure of Chlamydomonas reinhardtii HAP2 lacked this critical region. Here, we report a structure-guided alignment that reveals diversification of the proposed HAP2 fusion loops. Representative crystal structures show that in flowering plants, HAP2 has a single prominent fusion loop projecting an amphipathic helix at its apex, while in trypanosomes, three small nonpolar loops of HAP2 are poised to interact with the target membrane. A detailed structure-function analysis of the Arabidopsis HAP2 amphipathic fusion helix defines key residues that are essential for membrane insertion and for gamete fusion. Our study suggests that HAP2 may have evolved multiple modes of membrane insertion to accommodate the diversity of membrane environments it has encountered during eukaryotic evolution., Author summary The fusion of gamete plasma membranes is the fundamental cellular event that brings two parental cells together to form a new individual, yet we know surprisingly little about this process at the molecular level. HAPLESS 2 (HAP2) is a conserved sperm plasma membrane protein that is essential for gamete fusion in a diverse array of eukaryotes. It was recently shown to share a common ancestor with viral proteins that drive fusion of the viral envelope with host membranes, but its mechanism of action remained elusive, since the reported structure did not resolve the proposed membrane interaction surface. Here, we report two new HAP2 structures revealing that HAP2 has evolved diverse membrane interaction surfaces. In the flowering plants, HAP2 uses an amphipathic helix that presents nonpolar residues to the target membrane; in trypanosomes, the membrane interaction surface comprises three shallow nonpolar loops.

Published
2018
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4. Structure-Function Dissection of Pseudorabies Virus Glycoprotein B Fusion Loops

Author

Delphine Brun, Barbara G. Klupp, Melina Vallbracht, Gérard Pehau-Arnaudet, Ahmed Haouz, Pablo Guardado-Calvo, Félix A. Rey, Matteo Tassinari, Thomas C. Mettenleiter, Marija Backovic, Marie-Christine Vaney, Friedrich-Loeffler-Institut (FLI), Virologie Structurale - Structural Virology, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Microscopie ultrastructurale - Ultrapole (CITECH), Institut Pasteur [Paris], Cristallographie (Plateforme) - Crystallography (Platform), Work done by M.B., D.B., M.-C.V., P.G.-C., and F.A.R. was supported by Institut Pasteur and CNRS recurrent funding and the Pasteur-Weizmann/Servier International Prize (F.A.R., 2015). Work done by M.V., B.G.K., and T.C.M. was supported by DFG, grant Me 854/11-2., Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris] (IP)

Subjects
0301 basic medicine, Models, Molecular, Protein Conformation, [SDV]Life Sciences [q-bio], 030106 microbiology, Immunology, Plasma protein binding, Biology, Crystallography, X-Ray, Microbiology, 03 medical and health sciences, Protein structure, Viral envelope, Protein Domains, Viral Envelope Proteins, Virology, Lipid bilayer, Host cell membrane, Binding Sites, Lipid bilayer fusion, Virus Internalization, Fusion protein, Herpesvirus 1, Suid, Cell biology, Virus-Cell Interactions, 030104 developmental biology, Ectodomain, Insect Science, [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology, Liposomes, Mutation, Protein Binding
Abstract

Conserved across the family Herpesviridae , glycoprotein B (gB) is responsible for driving fusion of the viral envelope with the host cell membrane for entry upon receptor binding and activation by the viral gH/gL complex. Although crystal structures of the gB ectodomains of several herpesviruses have been reported, the membrane fusion mechanism has remained elusive. Here, we report the X-ray structure of the pseudorabies virus (PrV) gB ectodomain, revealing a typical class III postfusion trimer that binds membranes via its fusion loops (FLs) in a cholesterol-dependent manner. Mutagenesis of FL residues allowed us to dissect those interacting with distinct subregions of the lipid bilayer and their roles in membrane interactions. We tested 15 gB variants for the ability to bind to liposomes and further investigated a subset of them in functional assays. We found that PrV gB FL residues Trp187, Tyr192, Phe275, and Tyr276, which were essential for liposome binding and for fusion in cellular and viral contexts, form a continuous hydrophobic patch at the gB trimer surface. Together with results reported for other alphaherpesvirus gBs, our data suggest a model in which Phe275 from the tip of FL2 protrudes deeper into the hydrocarbon core of the lipid bilayer, while the side chains of Trp187, Tyr192, and Tyr276 form a rim that inserts into the more superficial interfacial region of the membrane to catalyze the fusion process. Comparative analysis with gBs from beta- and gamma-herpesviruses suggests that this membrane interaction model is valid for gBs from all herpesviruses. IMPORTANCE Herpesviruses are common human and animal pathogens that infect cells by entering via fusion of viral and cellular membranes. Central to the membrane fusion event is glycoprotein B (gB), which is the most conserved envelope protein across the herpesvirus family. Like other viral fusion proteins, gB anchors itself in the target membrane via two polypeptide segments called fusion loops (FLs). The molecular details of how gB FLs insert into the lipid bilayer have not been described. Here, we provide structural and functional data regarding key FL residues of gB from pseudorabies virus, a porcine herpesvirus of veterinary concern, which allows us to propose, for the first time, a molecular model to understand how the initial interactions by gBs from all herpesviruses with target membranes are established.

Published
2017
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5. Assessing Vacuolar Escape of Listeria Monocytogenes

Author

Javier Pizarro-Cerdá, Spencer L. Shorte, Anne Danckaert, Martin Sachse, Théodore Grenier, Damien Balestrino, Jennifer Fredlund, Pascale Cossart, Nathalie Aulner, Jost Enninga, Juan J. Quereda, Interactions Bactéries-Cellules (UIBC), Institut National de la Recherche Agronomique (INRA)-Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Microscopie ultrastructurale - Ultrapole (CITECH), Institut Pasteur [Paris] (IP), Laboratoire Microorganismes : Génome et Environnement (LMGE), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Centre National de la Recherche Scientifique (CNRS), Dynamique des Interactions Hôte-Pathogène - Dynamics of Host-Pathogen Interactions, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Imagopole (CITECH), Work in the laboratory of P.C. is supported by the Institut Pasteur (Unité des Interactions Bactéries-Cellules), the Institut National de la Santé et de la Recherche Médicale (Unité 604), the Institut National de la Recherche Agronomique (Unité Sous Contrat 2020), the Fondation Les Mousquetaires, and an European Research Council Advanced Grant (BacEpiCell 670823). The Imagopole is part of the FranceBioImaging infrastructure supported by the French National Research Agency (ANR-10-INSB-04-01, 'Investments for the Future') and is grateful to supports by Conseil de la Region Ile-de-France (program Sesame 2007, project Imagopole to S.S.) and from the Fondation Française pour la Recherche Médicale (FRM, Programme Grands Equipements to N.A.). J.E. is supported by the Institut Pasteur (PTR-460), by the Institut Pasteur Carnot-MIE program and by a European Research Council Starting Grant (RuptEffects 261166)., Collin M, We thank Servier Medical Art (http://www.servier.com/Powerpoint-image-bank) for providing drawings used in Fig. 1., ANR-10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010), ANR-15-CE15-0017,StopBugEntry,Identification des nouvelles molécules cellulaires cibles pour combattre les infections bactériennes(2015), ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), European Project: 670823,H2020,ERC-2014-ADG,BacCellEpi(2015), Institut National de la Recherche Agronomique (INRA)-Institut Pasteur [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Pasteur [Paris], Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Université d'Auvergne - Clermont-Ferrand I (UdA), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Pasteur [Paris]-Institut National de la Recherche Agronomique (INRA), Dynamique des Interactions Hôte-Pathogène, ANR-10-INBS-04-01/10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010), ANR-15-CE15-0017,StopBugEntry,Novel common host targets during bacterial invasion of humans(2015), ANR-10-LABX-62-IBEID,IBEID,Laboratoire d'Excellence 'Integrative Biology of Emerging Infectious Diseases'(2010), vicente, marie-therese, Développment d'une infrastructure française distribuée coordonnée - - France-BioImaging2010 - ANR-10-INBS-0004 - INBS - VALID, Identification des nouvelles molécules cellulaires cibles pour combattre les infections bactériennes - - StopBugEntry2015 - ANR-15-CE15-0017 - AAPG2015 - VALID, Integrative Biology of Emerging Infectious Diseases - - IBEID2010 - ANR-10-LABX-0062 - LABX - VALID, and Bacterial, cellular and epigenetic factors that control enteropathogenicity - BacCellEpi - - H20202015-10-01 - 2018-09-30 - 670823 - VALID

Subjects
0301 basic medicine, Phagocytosis, media_common.quotation_subject, [SDV]Life Sciences [q-bio], 030106 microbiology, education, Vacuole, Biology, medicine.disease_cause, Microbiology, 03 medical and health sciences, Listeria monocytogenes, medicine, Fluorescence Resonance Energy Transfer, Internalization, Pathogen, health care economics and organizations, media_common, Correlative light/electron microcopy (CLEM), CCF4, Listeriolysin O, Biological Transport, Förster resonance energy transfer (FRET) microscopy, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, Cell biology, [SDV] Life Sciences [q-bio], Microscopy, Electron, 030104 developmental biology, Förster resonance energy transfer, Microscopy, Fluorescence, Phospholipases, Vacuoles, [SDV.MP.BAC] Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology
Abstract

International audience; Listeria monocytogenes is a bacterial pathogen which invades and multiplies within non-professional phagocytes. Signaling cascades involved in cellular entry have been extensively analyzed, but the events leading to vacuolar escape remain less clear. In this chapter, we detail a microscopy FRET-based assay which allows quantitatively measuring L. monocytogenes infection and escape from its internalization vacuole, as well as a correlative light/electron microscopy method to investigate the morphological features of the vacuolar compartments containing L. monocytogenes.

Published
2016
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6. A Large Collection of Novel Nematode-Infecting Microsporidia and Their Diverse Interactions with Caenorhabditis elegans and Other Related Nematodes

Author

Zhang, Gaotian, Sachse, Martin, Prevost, Marie-Christine, Luallen, Robert J., Troemel, Emily R., Félix, Marie-Anne, Institut de biologie de l'ENS Paris (IBENS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Microscopie ultrastructurale - Ultrapole (CITECH), Institut Pasteur [Paris] (IP), University of California [San Diego] (UC San Diego), University of California (UC), This work was supported by: Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Inserm, Fondation pour la Recherche Médicale DEQ20150331704, Fondation Bettencourt-Schueller Coup d'Elan 2011, Fellowship from the China Scholarship Council, National Science Foundation Graduate Research fellowship, NIH R01GM114139 and Burroughs Wellcome Fund fellowship, and National Science Foundation Graduate Research Opportunities Worldwide. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript., Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut Pasteur [Paris], University of California, and Institut de biologie de l'ENS Paris (UMR 8197/1024) (IBENS)

Subjects
Nematoda, Cell Membranes, Pathogenesis, Pathology and Laboratory Medicine, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, Polymerase Chain Reaction, Microsporidiosis, Medicine and Health Sciences, Nematode Infections, lcsh:QH301-705.5, [SDV.MP.MYC]Life Sciences [q-bio]/Microbiology and Parasitology/Mycology, Phylogeny, Fungal Pathogens, [SDV.BA]Life Sciences [q-bio]/Animal biology, Animal Models, Experimental Organism Systems, Medical Microbiology, Host-Pathogen Interactions, Pathogens, Anatomy, Cellular Structures and Organelles, Research Article, lcsh:Immunologic diseases. Allergy, Mycology, [SDV.BID]Life Sciences [q-bio]/Biodiversity, Research and Analysis Methods, Microbiology, Model Organisms, Microscopy, Electron, Transmission, Virology, parasitic diseases, Parasitic Diseases, Animals, [SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology, Caenorhabditis elegans, Microbial Pathogens, Host Cells, fungi, Organisms, Biology and Life Sciences, Correction, Cell Biology, Invertebrates, Gastrointestinal Tract, lcsh:Biology (General), Microsporidia, Caenorhabditis, lcsh:RC581-607, Digestive System, Viral Transmission and Infection
Abstract

Microsporidia are fungi-related intracellular pathogens that may infect virtually all animals, but are poorly understood. The nematode Caenorhabditis elegans has recently become a model host for studying microsporidia through the identification of its natural microsporidian pathogen Nematocida parisii. However, it was unclear how widespread and diverse microsporidia infections are in C. elegans or other related nematodes in the wild. Here we describe the isolation and culture of 47 nematodes with microsporidian infections. N. parisii is found to be the most common microsporidia infecting C. elegans in the wild. In addition, we further describe and name six new species in the Nematocida genus. Our sampling and phylogenetic analysis further identify two subclades that are genetically distinct from Nematocida, and we name them Enteropsectra and Pancytospora. Interestingly, unlike Nematocida, these two genera belong to the main clade of microsporidia that includes human pathogens. All of these microsporidia are horizontally transmitted and most specifically infect intestinal cells, except Pancytospora epiphaga that replicates mostly in the epidermis of its Caenorhabditis host. At the subcellular level in the infected host cell, spores of the novel genus Enteropsectra show a characteristic apical distribution and exit via budding off of the plasma membrane, instead of exiting via exocytosis as spores of Nematocida. Host specificity is broad for some microsporidia, narrow for others: indeed, some microsporidia can infect Oscheius tipulae but not its sister species Oscheius sp. 3, and conversely some microsporidia found infecting Oscheius sp. 3 do not infect O. tipulae. We also show that N. ausubeli fails to strongly induce in C. elegans the transcription of genes that are induced by other Nematocida species, suggesting it has evolved mechanisms to prevent induction of this host response. Altogether, these newly isolated species illustrate the diversity and ubiquity of microsporidian infections in nematodes, and provide a rich resource to investigate host-parasite coevolution in tractable nematode hosts., Author Summary Microsporidia are microbial parasites that live inside their host cells and can cause disease in humans and many other animals. The small nematode worm Caenorhabditis elegans has recently become a convenient model host for studying microsporidian infections. In this work, we sample Caenorhabditis and other small nematodes and 47 associated microsporidian strains from the wild. We characterize the parasites for their position in the evolutionary tree of microsporidia and for their lifecycle and morphology. We find several new species and genera, especially some that are distantly related to the previously known Nematocida parisii and instead closely related to human pathogens. We find that some of these species have a narrow host range. We studied two species in detail using electron microscopy and uncover a new likely mode of exit from the host cell, by budding off the host cell plasma membrane rather than by fusion of a vesicle to the plasma membrane as in N. parisii. We also find a new species that infects the epidermis and muscles of Caenorhabditis rather than the host intestinal cells and is closely related to human pathogens. Finally, we find that one Nematocida species fails to elicit the same host response that other Nematocida species do. These new microsporidia open up many windows into microsporidia biology and opportunities to investigate host-parasite coevolution in the C. elegans system.

Published
2016
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7. Differential identity of Filopodia and Tunneling Nanotubes revealed by the opposite functions of actin regulatory complexes

Author

Andrea Disanza, Chiara Zurzolo, Giorgio Scita, Esthel Pénard, Diégo Cordero Cervantes, Elise Delage, Christine Schmitt, Sylvie Syan, Trafic membranaire et Pathogénèse, Institut Pasteur [Paris], Microscopie ultrastructurale - Ultrapole (CITECH), IFOM, Istituto FIRC di Oncologia Molecolare (IFOM), Università degli Studi di Milano [Milano] (UNIMI), We gratefully acknowledge the kind financial support of the Institut Pasteur (Paris), the France–BioImaging infrastructure network supported by the French National Research Agency (ANR-10–INSB–04, Investments for the future), and the Région Ile-de-France (program DIM-Malinf ). We thank Dr. Jean-Yves Tinevez and Dr. Audrey Salles from Imagopole at Institut Pasteur for their help with microscopy imaging. We thank Dr. Sophie Novault from the Flow Cytometry Platform at Institut Pasteur for her help with flow cytometry experiments. We thank Dr. Fabrice De Chaumont from the Bioimage Analysis Unit at Institut Pasteur for his help with the software: ICY. E.D. is a recipient of the Bourse Carnot-Pasteur Maladies Infectieuses and the Bourse Pasteur-Roux, Institut Pasteur. This work is supported by research grants from the Agence Nationale de la Recherche (ANR-14-JPCD-0002-01 and ANR-16-CE16-0019-Neurotunn), AIC RECH COLLECT CYANOBAC, and Equipe FRM (Fondation Recherche Médicale) 2014 (DEQ20140329557) to C.Z., ANR-10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010), ANR-14-JPCD-0002,Neutargets,Targeting the propagation of pathogenic protein assemblies in neurodegenerative disease(2014), ANR-16-CE16-0019,Neurotunn,Role des nanotubes membranaires dans la propagation d'agrégats protéiques impliqués dans les maladie neurodégénératives(2016), Institut Pasteur [Paris] (IP), Università degli Studi di Milano = University of Milan (UNIMI), Delage, E., Cervantes, D. C., Penard, E., Schmitt, C., Syan, S., Disanza, A., Scita, G., and Zurzolo, C.

Subjects
0301 basic medicine, Cell signaling, Green Fluorescent Proteins, Nerve Tissue Proteins, CDC42, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, macromolecular substances, Cell Communication, Biology, Endocytosis, Green Fluorescent Protein, Article, EPS8, 03 medical and health sciences, Mice, Animals, Pseudopodia, cdc42 GTP-Binding Protein, Actin, Adaptor Proteins, Signal Transducing, Neurons, Multidisciplinary, Nanotubes, 030102 biochemistry & molecular biology, Endocytosi, Animal, Cell Membrane, Microfilament Proteins, Signal transducing adaptor protein, Brain, Microfilament Protein, Neuron, Phosphoproteins, Actins, Cell biology, Nanotube, Actin Cytoskeleton, 030104 developmental biology, Cell Adhesion Molecule, Phosphoprotein, Nerve Tissue Protein, Microscopy, Electron, Scanning, Filopodia, Cell Adhesion Molecules, Intracellular
Abstract

Tunneling Nanotubes (TNTs) are actin enriched filopodia-like protrusions that play a pivotal role in long-range intercellular communication. Different pathogens use TNT-like structures as “freeways” to propagate across cells. TNTs are also implicated in cancer and neurodegenerative diseases, making them promising therapeutic targets. Understanding the mechanism of their formation, and their relation with filopodia is of fundamental importance to uncover their physiological function, particularly since filopodia, differently from TNTs, are not able to mediate transfer of cargo between distant cells. Here we studied different regulatory complexes of actin, which play a role in the formation of both these structures. We demonstrate that the filopodia-promoting CDC42/IRSp53/VASP network negatively regulates TNT formation and impairs TNT-mediated intercellular vesicle transfer. Conversely, elevation of Eps8, an actin regulatory protein that inhibits the extension of filopodia in neurons, increases TNT formation. Notably, Eps8-mediated TNT induction requires Eps8 bundling but not its capping activity. Thus, despite their structural similarities, filopodia and TNTs form through distinct molecular mechanisms. Our results further suggest that a switch in the molecular composition in common actin regulatory complexes is critical in driving the formation of either type of membrane protrusion.

Published
2016
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8. Analysis of a Spontaneous Non-Motile and Avirulent Mutant Shows That FliM Is Required for Full Endoflagella Assembly in Leptospira interrogans

Author

Célia Fontana, Mathieu Picardeau, Nadia Benaroudj, Nathalie Michele Cachet, Olivier Gorgette, David Gasparini, Natalia Bomchil, Ambroise Lambert, Biologie des Spirochètes / Biology of Spirochetes, Institut Pasteur [Paris], Laboratoire Lyon Gerland, MERIAL, Centre de Recherche Clinique de Saint Vulbas, Microscopie ultrastructurale - Ultrapole (CITECH), This work was funded by the Institut Pasteur (http://www.pasteur.fr), FUI 14 (Fonds Unique Interministériel) 'COVALEPT', BPI France (http://www.bpifrance.fr/), Association Nationale de la Recherche et de la Technologie (http://www.anrt.asso.fr/), and Merial SAS France (http://www.merial.com). The funder provided support in the form of salaries for authors [CF, DG, NC, N. Benaroudj, MP, N. Bomchil, OG, AL] and research materials, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript., and Institut Pasteur [Paris] (IP)

Subjects
0301 basic medicine, lcsh:Medicine, Pathology and Laboratory Medicine, Cell morphology, Biochemistry, Medicine and Health Sciences, lcsh:Science, Leptospira, Mammals, MESH: Gene Expression Regulation, Bacterial, MESH: Genetic Complementation Test, Multidisciplinary, Virulence, biology, Bacterial Pathogens, 3. Good health, MESH: Leptospira interrogans/ultrastructure, Leptospira Interrogans, Cell Motility, MESH: Leptospira interrogans/physiology, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Flagella, Medical Microbiology, Vertebrates, Hamsters, Cellular Structures and Organelles, Pathogens, Leptospira interrogans, Research Article, Pathogen Motility, MESH: Mutation, Virulence Factors, Motor Proteins, 030106 microbiology, Motility, Flagellum, MESH: Bacterial Proteins/genetics, Microbiology, Rodents, Motor protein, 03 medical and health sciences, Bacterial Proteins, Molecular Motors, Animals, MESH: Virulence/genetics, Microbial Pathogens, [SDV.GEN]Life Sciences [q-bio]/Genetics, Bacteria, Genetic Complementation Test, lcsh:R, Organisms, Biology and Life Sciences, Proteins, Cell Biology, Flagellar Motility, Gene Expression Regulation, Bacterial, Periplasmic space, MESH: Flagella/physiology, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 030104 developmental biology, MESH: Flagella/ultrastructure, Amniotes, Mutation, lcsh:Q
Abstract

International audience; Pathogenic Leptospira strains are responsible for leptospirosis, a worldwide emerging zoonotic disease. These spirochetes are unique amongst bacteria because of their corkscrew-like cell morphology and their periplasmic flagella. Motility is reported as an important virulence determinant, probably favoring entry and dissemination of pathogenic Leptospira in the host. However, proteins constituting the periplasmic flagella and their role in cell shape, motility and virulence remain poorly described. In this study, we characterized a spontaneous L. interrogans mutant strain lacking motility, correlated with the loss of the characteristic hook-shaped ends, and virulence in the animal model. Whole genome sequencing allowed the identification of one nucleotide deletion in the fliM gene resulting in a premature stop codon, thereby preventing the production of flagellar motor switch protein FliM. Genetic complementation restored cell morphology, motility and virulence comparable to those of wild type cells. Analyses of purified periplasmic flagella revealed a defect in flagella assembly, resulting in shortened flagella compared to the wild type strain. This also correlated with a lower amount of major filament proteins FlaA and FlaB. Altogether, these findings demonstrate that FliM is required for full and correct assembly of the flagella which is essential for motility and virulence.

Published
2016
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9. Bioimage analysis of Shigella infection reveals targeting of colonic crypts

Author

Maryse Moya-Nilges, Giulia Nigro, Martin Sachse, Philippe J. Sansonetti, Ellen T. Arena, Jean-Yves Tinevez, François-Xavier Campbell-Valois, Katharina Nothelfer, Spencer L. Shorte, Benoit S. Marteyn, Pathogénie microbienne moléculaire, Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Imagerie Dynamique (Plate-Forme) (PFID), Institut Pasteur [Paris] (IP), Microscopie ultrastructurale - Ultrapole (CITECH), Collège de France - Chaire Microbiologie et Maladies infectieuses, Collège de France (CdF (institution)), E.T.A. was a Pasteur Foundation and Pasteur-Roux Fellow. F.-X.C.-V. was a Canadian Institutes of Health Research, European Molecular Biology Organization, Marie-Curie, and Fondation de la Recherche Médicale Fellow. P.J.S. is a Howard Hughes Medical Institute Senior International Research Scholar. This work was supported by the European Research Council (PS Advanced Grants 232798 and 339579), France Bioimaging Infrastructure, supported by the French National Research Agency ANR-10-INSB-04-01 Program Investments for the Future, and the Wellcome Trust., We thank Sèbastien Simard (Welcome Trust, London) for his contributions in OMERO and Pamela Schnupf and Claude Parsot for helpful discussions., European Project: 232798,EC:FP7:ERC,ERC-2008-AdG,HOMEOEPITH(2009), European Project: 339579,EC:FP7:ERC,ERC-2013-ADG,DECRYPT(2014), Tinevez, Jean-Yves, Homeostasis and rupture of the gut epithelium in the presence of commensals and pathogens - HOMEOEPITH - - EC:FP7:ERC2009-02-01 - 2013-07-31 - 232798 - VALID, Decrypting signals in the crypt. - DECRYPT - - EC:FP7:ERC2014-04-01 - 2019-03-31 - 339579 - VALID, Institut Pasteur [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Pasteur [Paris], and Chaire Microbiologie et Maladies infectieuses

Subjects
Fluorescence-lifetime imaging microscopy, Colon, Confocal, [SDV]Life Sciences [q-bio], Crypt, Guinea Pigs, MESH: Intestinal Mucosa / microbiology, MESH: Shigella flexneri / pathogenicity, Biology, medicine.disease_cause, Microbiology, Shigella flexneri, MESH: Guinea Pigs, tissue microbiology, Intestinal mucosa, In vivo, medicine, Animals, Humans, Shigella, MESH: Animals, bioimage analysis, intestinal crypts, Intestinal Mucosa, [SDV.MP] Life Sciences [q-bio]/Microbiology and Parasitology, Dysentery, Bacillary, Multidisciplinary, MESH: Humans, biology.organism_classification, digestive system diseases, 3. Good health, Cell biology, MESH: Dysentery, Bacillary / pathology, [SDV] Life Sciences [q-bio], [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, PNAS Plus, MESH: Colon / microbiology, Infectious agent, host–pathogen interactions
Abstract

International audience; Few studies within the pathogenic field have used advanced imaging and analytical tools to quantitatively measure pathogenicity in vivo. In this work, we present a novel approach for the investigation of host-pathogen processes based on medium-throughput 3D fluorescence imaging. The guinea pig model for Shigella flexneri invasion of the colonic mucosa was used to monitor the infectious process over time with GFP-expressing S. flexneri. A precise quantitative imaging protocol was devised to follow individual S. flexneri in a large tissue volume. An extensive dataset of confocal images was obtained and processed to extract specific quantitative information regarding the progression of S. flexneri infection in an unbiased and exhaustive manner. Specific parameters included the analysis of S. flexneri positions relative to the epithelial surface, S. flexneri density within the tissue, and volume of tissue destruction. In particular, at early time points, there was a clear association of S. flexneri with crypts, key morphological features of the colonic mucosa. Numerical simulations based on random bacterial entry confirmed the bias of experimentally measured S. flexneri for early crypt targeting. The application of a correlative light and electron microscopy technique adapted for thick tissue samples further confirmed the location of S. flexneri within colonocytes at the mouth of crypts. This quantitative imaging approach is a novel means to examine host-pathogen systems in a tailored and robust manner, inclusive of the infectious agent.

Published
2015
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10. SUN proteins belong to a novel family of β-(1,3)-glucan-modifying enzymes involved in fungal morphogenesis

Author

Christine Schmitt, Christophe d'Enfert, Audrey Nesseir, Anne Beauvais, Patrick England, Vishukumar Aimanianda, Rémi Beau, Arnaud Firon, Marie-Christine Prévost, Amandine Gastebois, Sophie Bachellier-Bassi, Jean-Paul Latgé, Isabelle Mouyna, Aspergillus, Institut Pasteur [Paris], Biologie et Pathogénicité fongiques, Institut Pasteur [Paris]-Institut National de la Recherche Agronomique (INRA), Microscopie ultrastructurale (plate-forme), Biochimie et Biophysique des Macromolécules (Plate-forme), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), This work was supported by grants from the European Commission (Galar Fungail 2, MRTN-CT-2003-504148, FINSysB, PITN-GA-2008-214004) (to C. d. E.) and the European Science Foundation (ESF) Fuminomics, Partenariat Sanofi-aventis-Aviesan (ITMO Maladies Infectieuses, Sanofi Aventis Research & Development TSU ID (SAR&D) TSU ID/Sanofi-Pasteur), and Agence Nationale de Recherches (ANR) (Grant 09-BLAN-0287) (to J. P. L.), ANR-09-BLAN-0287,REMODELE,Nouvelles voies métaboliques essentielles pour la biosynthèse de la paroi des champignons(2009), European Project: 214004,PEOPLE,FP7-PEOPLE-2007-1-1-ITN,FINSYSB(2008), Institut Pasteur [Paris] (IP), Biologie et Pathogénicité fongiques (BPF), Institut National de la Recherche Agronomique (INRA)-Institut Pasteur [Paris] (IP), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Institut Pasteur [Paris], Biophysique des macromolécules et de leurs interactions, ANR Grant 09-BLAN-0287,ANR Grant 09-BLAN-0287,Grant 09-BLAN-0287, Institut National de la Recherche Agronomique (INRA) - Institut Pasteur [Paris], Microscopie ultrastructurale - Ultrapole (CITECH), Biophysique des macromolécules et leurs interactions, and Institut Pasteur [Paris] - Centre National de la Recherche Scientifique (CNRS)

Subjects
Hyphal growth, MESH : Spores, Fungal, MESH : Molecular Sequence Data, Glycosylation, MESH: Sequence Homology, Amino Acid, Conidiation, Gene Expression, Oligosaccharides, Glycobiology and Extracellular Matrices, MESH: Amino Acid Sequence, Biochemistry, Aspergillus fumigatus, Cell Wall, Gene Expression Regulation, Fungal, Candida albicans, Morphogenesis, MESH : Fungal Proteins, skin and connective tissue diseases, [SDV.MP.MYC]Life Sciences [q-bio]/Microbiology and Parasitology/Mycology, 0303 health sciences, integumentary system, MESH : Amino Acid Sequence, Hydrolysis, MESH : Glycosylation, Glucan Hydrolase Activity, SUN, MESH : Protein Binding, MESH : Glycoside Hydrolases, Spores, Fungal, MESH: Glycosylation, MESH : Sequence Homology, Amino Acid, Cell biology, [SDV] Life Sciences [q-bio], Aspergillus, CELL-WALL BIOGENESIS, MOTOR-LIKE DOMAIN, ASPERGILLUS-FUMIGATUS, CANDIDA-ALBICANS, SCHIZOSACCHAROMYCES-POMBE, SACCHAROMYCES-CEREVISIAE, BIOFILM FORMATION, BETA-GLUCOSIDASE, CHITIN SYNTHASES, GENE, MESH: Fungal Proteins, MESH: Aspergillus fumigatus, MESH: Gene Expression Regulation, Fungal, MESH: Hydrolysis, Protein Binding, CAZy, MESH: Gene Expression, Hypha, MESH : Candida albicans, Glycoside Hydrolases, Molecular Sequence Data, Hyphae, MESH: Glycoproteins, Biology, Microbiology, Cell wall, Fungal Proteins, 03 medical and health sciences, MESH : Hydrolysis, MESH: Hyphae, MESH: Spores, Fungal, MESH : Gene Expression Regulation, Fungal, MESH: Glycoside Hydrolases, MESH: Protein Binding, Amino Acid Sequence, Molecular Biology, 030304 developmental biology, MESH : Protein Processing, Post-Translational, Glycoproteins, MESH: Molecular Sequence Data, Sequence Homology, Amino Acid, 030306 microbiology, MESH: Candida albicans, MESH : Oligosaccharides, Cell Biology, biology.organism_classification, MESH : Glycoproteins, [SDV.MP.MYC] Life Sciences [q-bio]/Microbiology and Parasitology/Mycology, Yeast, MESH: Morphogenesis, MESH : Gene Expression, MESH : Morphogenesis, MESH : Aspergillus fumigatus, MESH: Protein Processing, Post-Translational, MESH : Hyphae, Carbohydrate-binding Protein, Protein Processing, Post-Translational, MESH: Oligosaccharides, Biogenesis
Abstract

International audience; BACKGROUND:SUN proteins are involved in yeast morphogenesis, but their function is unknown.RESULTS:SUN protein plays a role in the Aspergillus fumigatus morphogenesis. Biochemical properties of recombinant SUN proteins were elucidated.CONCLUSION:Both Candida albicans and Aspergillus fumigatus sun proteins show a β-(1,3)-glucanase activity.SIGNIFICANCE:The mode of action of SUN proteins on β-(1,3)-glucan is unique, new, and original. In yeasts, the family of SUN proteins has been involved in cell wall biogenesis. Here, we report the characterization of SUN proteins in a filamentous fungus, Aspergillus fumigatus. The function of the two A. fumigatus SUN genes was investigated by combining reverse genetics and biochemistry. During conidial swelling and mycelial growth, the expression of AfSUN1 was strongly induced, whereas the expression of AfSUN2 was not detectable. Deletion of AfSUN1 negatively affected hyphal growth and conidiation. A closer examination of the morphological defects revealed swollen hyphae, leaky tips, intrahyphal growth, and double cell wall, suggesting that, like in yeast, AfSun1p is associated with cell wall biogenesis. In contrast to AfSUN1, deletion of AfSUN2 either in the parental strain or in the AfSUN1 single mutant strain did not affect colony and hyphal morphology. Biochemical characterization of the recombinant AfSun1p and Candida albicans Sun41p showed that both proteins had a unique hydrolysis pattern: acting on β-(1,3)-oligomers from dimer up to insoluble β-(1,3)-glucan. Referring to the CAZy database, it is clear that fungal SUN proteins represent a new family of glucan hydrolases (GH132) and play an important morphogenetic role in fungal cell wall biogenesis and septation.

Published
2013
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11. Crystal structure of glycoprotein C from a hantavirus virus in the post-fusion conformation

Author

Gérard Pehau-Arnaudet, Pablo Guardado-Calvo, Félix A. Rey, M. Alejandra Tortorici, Jean Luc Jestin, Scott A. Jeffers, Patrick England, Nicole D. Tischler, Eva Stettner, Jimena Pérez-Vargas, Eduardo A Bignon, Virologie Structurale - Structural Virology, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Molecular Virology Laboratory, Fundación Ciencia & Vida, Microscopie ultrastructurale - Ultrapole (CITECH), Institut Pasteur [Paris] (IP), Biophysique des macromolécules et leurs interactions, FAR and PGC acknowledge support the Infect-ERA IMI European network, program 'HantaHunt' and its coordinator, Professor Andreas Herrmann. FAR also received funding from the 'Integrative Biology of Emerging Infectious Diseases' Labex (Laboratoire d'Excellence ) grant N° ANR-10-LABX-62-IBEID (French Government's 'Investissements d'Avenir' program). ES was funded as 'Experienced Researche' (ER) by the Marie Curie Training Network 'Virus Entry' (Call:FP7-PEOPLE-2007-1-1-ITN. NDT received support from FONDECYT 1140050 and Basal PFB-16 grants from CONICYT (Chile). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript., ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), European Project: 235649,EC:FP7:PEOPLE,FP7-PEOPLE-ITN-2008,VIRUS ENTRY(2009), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris]

Subjects
RNA viruses, Retinal Ganglion Cells, 0301 basic medicine, Orthohantavirus, Orthobunyavirus, Protein Conformation, viruses, Cell Membranes, Andes virus, Pathology and Laboratory Medicine, medicine.disease_cause, Membrane Fusion, Physical Chemistry, Viral Envelope Proteins, Animal Cells, Bunyaviruses, Medicine and Health Sciences, Biology (General), Neurons, Crystallography, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Physics, virus diseases, Condensed Matter Physics, 3. Good health, Chemistry, Medical Microbiology, Viral Pathogens, [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology, Viruses, Physical Sciences, Crystal Structure, Mathematisch-Naturwissenschaftliche Fakultät, Pathogens, Cellular Structures and Organelles, Cellular Types, Research Article, Hantavirus, Ganglion Cells, QH301-705.5, Viral protein, 030106 microbiology, Immunology, Viral Structure, Biology, Microbiology, Structure-Activity Relationship, 03 medical and health sciences, Viral entry, Virology, Genetics, medicine, Solid State Physics, Animals, Humans, ddc:610, Vesicles, Microbial Pathogens, Molecular Biology, Institut für Biochemie und Biologie, Hantaan virus, Glycoproteins, Hantavirus pulmonary syndrome, Biology and life sciences, Chemical Bonding, Organisms, Afferent Neurons, Lipid bilayer fusion, Hydrogen Bonding, Cell Biology, RC581-607, Surface Plasmon Resonance, Fusion protein, 030104 developmental biology, Cellular Neuroscience, Liposomes, Bunyavirus, Parasitology, Immunologic diseases. Allergy, viral fusion, Neuroscience
Abstract

Hantaviruses are zoonotic viruses transmitted to humans by persistently infected rodents, giving rise to serious outbreaks of hemorrhagic fever with renal syndrome (HFRS) or of hantavirus pulmonary syndrome (HPS), depending on the virus, which are associated with high case fatality rates. There is only limited knowledge about the organization of the viral particles and in particular, about the hantavirus membrane fusion glycoprotein Gc, the function of which is essential for virus entry. We describe here the X-ray structures of Gc from Hantaan virus, the type species hantavirus and responsible for HFRS, both in its neutral pH, monomeric pre-fusion conformation, and in its acidic pH, trimeric post-fusion form. The structures confirm the prediction that Gc is a class II fusion protein, containing the characteristic β-sheet rich domains termed I, II and III as initially identified in the fusion proteins of arboviruses such as alpha- and flaviviruses. The structures also show a number of features of Gc that are distinct from arbovirus class II proteins. In particular, hantavirus Gc inserts residues from three different loops into the target membrane to drive fusion, as confirmed functionally by structure-guided mutagenesis on the HPS-inducing Andes virus, instead of having a single “fusion loop”. We further show that the membrane interacting region of Gc becomes structured only at acidic pH via a set of polar and electrostatic interactions. Furthermore, the structure reveals that hantavirus Gc has an additional N-terminal “tail” that is crucial in stabilizing the post-fusion trimer, accompanying the swapping of domain III in the quaternary arrangement of the trimer as compared to the standard class II fusion proteins. The mechanistic understandings derived from these data are likely to provide a unique handle for devising treatments against these human pathogens., Author Summary Hantaviruses belong to the Bunyaviridae family of enveloped viruses. This family englobes in total five established genera: Tospovirus (infecting plants), and Phlebovirus, Orthobunyavirus, Nairovirus and Hantavirus infecting animals, some of which cause serious disease in humans. An important characteristic of the hantaviruses is that they are not transmitted to humans by arthropod vectors, as those from the other genera, but by direct exposure to excretions from infected small mammals. As all enveloped viruses, they require the activity of a membrane fusogenic protein, Gc, for entry into their target cells. Our structural analysis of the hantavirus fusion protein Gc led to the identification of a conserved pattern of cysteines involved in disulfide bonds stabilizing the Gc fold. This motif is matched exclusively by all of the available bunyavirus Gc sequences in the database, with the notable exception of phlebovirus Gc, which appears closer in structure to the fusion proteins of other families of arthropod-borne viruses, such as the flaviviruses and alphaviruses. This analysis further suggests mechanistic similarities with hantaviruses in the fusion mechanism of viruses in the remaining three most closely related bunyavirus genera, which we propose belong to a new separate sub-class of fusion proteins with a multipartite membrane targeting region.

Published
2016
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12. The entry of Salmonella in a distinct tight compartment revealed at high temporal and ultrastructural resolution

Author

Michael Elbaum, Virginie Stévenin, Jacomine Krijnse-Locker, Katya Rechav, Jennifer Fredlund, Patricia Latour-Lambert, Jost Enninga, Adeline Mallet, Allon Weiner, José Carlos Santos, Dynamique des Interactions Hôte-Pathogène - Dynamics of Host-Pathogen Interactions, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Department of Materials and Interfaces [Rehovot, Israël], Weizmann Institute of Science [Rehovot, Israël], Microscopie ultrastructurale - Ultrapole (CITECH), Institut Pasteur [Paris], This work was funded by grants from the Pasteur‐Weizmann Foundation to J. E., by a fellowship from the Pasteur Foundation to J. F. by the FCT (SFRH/BD/51006/2010), and an Institut Pasteur PTR grant to J. C. S. by fellowships from the Pasteur‐Weizmann Foundation and the FRM to A. W., by a fellowship from the University Paris Diderot allocated by the ENS Cachan, Université Paris‐Saclay, and a grant from the FRM to V.S., and by grants from the ANR (StopBugEntry), and the European Research Council (Starting grant 'Rupteffects' and Consolidator grant 'EndoSubvert') to J. E., ANR-15-CE15-0017,StopBugEntry,Identification des nouvelles molécules cellulaires cibles pour combattre les infections bactériennes(2015), European Project: 261166,EC:FP7:ERC,ERC-2010-StG_20091118,RUPTEFFECTS(2011), European Project: 682809,EndoSubvert(2017), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), and Institut Pasteur [Paris] (IP)

Subjects
0301 basic medicine, Salmonella, Membrane ruffling, intracellular trafficking, 030106 microbiology, Immunology, Vacuole, medicine.disease_cause, Microbiology, 03 medical and health sciences, Cytosol, Virology, [SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], medicine, Humans, Compartment (development), Secretion, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], host cell invasion, biology, Salmonella enterica, Epithelial Cells, biology.organism_classification, Cell biology, correlative light electron mciroscopy, Host-Pathogen Interactions, Salmonella Infections, Ultrastructure, macropinosomes, Intracellular, HeLa Cells
Abstract

International audience; Salmonella enterica induces membrane ruffling and genesis of macropinosomes during its interactions with epithelial cells. This is achieved through the type three secretion system-1, which first mediates bacterial attachment to host cells and then injects bacterial effector proteins to alter host behaviour. Next, Salmonella enters into the targeted cell within an early membrane-bound compartment that matures into a slow growing, replicative niche called the Salmonella Containing Vacuole (SCV). Alternatively, the pathogen disrupts the membrane of the early compartment and replicate at high rate in the cytosol. Here, we show that the in situ formed macropinosomes, which have been previously postulated to be relevant for the step of Salmonella entry, are key contributors for the formation of the mature intracellular niche of Salmonella. We first clarify the primary mode of type three secretion system-1 induced Salmonella entry into epithelial cells by combining classical fluorescent microscopy with cutting edge large volume electron microscopy. We observed that Salmonella, similarly to Shigella, enters epithelial cells inside tight vacuoles rather than in large macropinosomes. We next apply this technology to visualise rupturing Salmonella containing compartments, and we use extended time-lapse microscopy to establish early markers that define which Salmonella will eventually hyper replicate. We show that at later infection stages, SCVs harbouring replicating Salmonella have previously fused with the in situ formed macropinosomes. In contrast, such fusion events could not be observed for hyper-replicating Salmonella, suggesting that fusion of the Salmonella entry compartment with macropinosomes is the first committed step of SCV formation.

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