351
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Billings EA, Lee CS, Owen KA, D'Souza RS, Ravichandran KS, Casanova JE. The adhesion GPCR BAI1 mediates macrophage ROS production and microbicidal activity against Gram-negative bacteria. Sci Signal 2016; 9:ra14. [PMID: 26838550 PMCID: PMC4894535 DOI: 10.1126/scisignal.aac6250] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The detection of microbes and initiation of an innate immune response occur through pattern recognition receptors (PRRs), which are critical for the production of inflammatory cytokines and activation of the cellular microbicidal machinery. In particular, the production of reactive oxygen species (ROS) by the NADPH oxidase complex is a critical component of the macrophage bactericidal machinery. We previously characterized brain-specific angiogenesis inhibitor 1 (BAI1), a member of the adhesion family of G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors (GPCRs), as a PRR that mediates the selective phagocytic uptake of Gram-negative bacteria by macrophages. We showed that BAI1 promoted phagosomal ROS production through activation of the Rho family guanosine triphosphatase (GTPase) Rac1, thereby stimulating NADPH oxidase activity. Primary BAI1-deficient macrophages exhibited attenuated Rac GTPase activity and reduced ROS production in response to several Gram-negative bacteria, resulting in impaired microbicidal activity. Furthermore, in a peritoneal infection model, BAI1-deficient mice exhibited increased susceptibility to death by bacterial challenge because of impaired bacterial clearance. Together, these findings suggest that BAI1 mediates the clearance of Gram-negative bacteria by stimulating both phagocytosis and NADPH oxidase activation, thereby coupling bacterial detection to the cellular microbicidal machinery.
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Affiliation(s)
- Emily A Billings
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Chang Sup Lee
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Katherine A Owen
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Ryan S D'Souza
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Kodi S Ravichandran
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - James E Casanova
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA. Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA.
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352
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Yeo JC, Wall AA, Luo L, Stow JL. Sequential recruitment of Rab GTPases during early stages of phagocytosis. CELLULAR LOGISTICS 2016; 6:e1140615. [PMID: 27217977 DOI: 10.1080/21592799.2016.1140615] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/17/2015] [Accepted: 01/05/2016] [Indexed: 12/31/2022]
Abstract
The phagocytosis and destruction of pathogens and dead cells by macrophages is important for innate immunity and tissue maintenance. Multiple Rab family GTPases engage effector molecules to coordinate the early stages of phagocytosis, which include rapid changes in actin polymerization, membrane phospholipids, trafficking and the activation of receptors. Defining the spatiotemporal, sequential recruitment of these Rabs is critical for insights into how phagocytosis is initiated and coordinated. Here, we screened GFP-tagged Rabs expressed in fixed and live cells to identify and stratify those recruited to early phagocytic membranes at stages defined by phospholipid transitions. We propose a sequence of Rabs 35, 13, 8a, 8b, 27a, 10, and 31 that precedes and accompanies phagocytic cup closure, followed after closure by recruitment of endosomal Rabs 5a, 5b, 5c, 14, and 11. Reducing the expression of individual Rabs by siRNA knockdown, notably Rabs 35 and 13, disrupts phagocytosis prior to phagocytic cup closure, confirming a known role for Rab35 and revealing anew the involvement of Rab13. The results enhance our understanding of innate immune responses in macrophages by revealing the sequence of Rabs that initiates phagocytosis.
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Affiliation(s)
- Jeremy C Yeo
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Queensland, Australia
| | - Adam A Wall
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Queensland, Australia
| | - Lin Luo
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Queensland, Australia
| | - Jennifer L Stow
- Institute for Molecular Bioscience, The University of Queensland , Brisbane, Queensland, Australia
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353
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Niedergang F, Di Bartolo V, Alcover A. Comparative Anatomy of Phagocytic and Immunological Synapses. Front Immunol 2016; 7:18. [PMID: 26858721 PMCID: PMC4729869 DOI: 10.3389/fimmu.2016.00018] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 01/14/2016] [Indexed: 11/17/2022] Open
Abstract
The generation of phagocytic cups and immunological synapses are crucial events of the innate and adaptive immune responses, respectively. They are triggered by distinct immune receptors and performed by different cell types. However, growing experimental evidence shows that a very close series of molecular and cellular events control these two processes. Thus, the tight and dynamic interplay between receptor signaling, actin and microtubule cytoskeleton, and targeted vesicle traffic are all critical features to build functional phagosomes and immunological synapses. Interestingly, both phagocytic cups and immunological synapses display particular spatial and temporal patterns of receptors and signaling molecules, leading to the notion of “phagocytic synapse.” Here, we discuss both types of structures, their organization, and the mechanisms by which they are generated and regulated.
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Affiliation(s)
- Florence Niedergang
- U1016, Institut Cochin, INSERM, Paris, France; UMR 8104, CNRS, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Vincenzo Di Bartolo
- Lymphocyte Cell Biology Unit, Department of Immunology, Institut Pasteur, Paris, France; U1221, INSERM, Paris, France
| | - Andrés Alcover
- Lymphocyte Cell Biology Unit, Department of Immunology, Institut Pasteur, Paris, France; U1221, INSERM, Paris, France
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354
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Steffen A, Stradal TEB, Rottner K. Signalling Pathways Controlling Cellular Actin Organization. Handb Exp Pharmacol 2016; 235:153-178. [PMID: 27757765 DOI: 10.1007/164_2016_35] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The actin cytoskeleton is essential for morphogenesis and virtually all types of cell shape changes. Reorganization is per definition driven by continuous disassembly and re-assembly of actin filaments, controlled by major, ubiquitously operating machines. These are specifically employed by the cell to tune its activities in accordance with respective environmental conditions or to satisfy specific needs.Here we sketch some fundamental signalling pathways established to contribute to the reorganization of specific actin structures at the plasma membrane. Rho-family GTPases are at the core of these pathways, and dissection of their precise contributions to actin reorganization in different cell types and tissues will thus continue to improve our understanding of these important signalling nodes. Furthermore, we will draw your attention to the emerging theme of actin reorganization on intracellular membranes, its functional relation to Rho-GTPase signalling, and its relevance for the exciting phenomenon autophagy.
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Affiliation(s)
- Anika Steffen
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.
| | - Klemens Rottner
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.,Zoological Institute, Technische Universität Braunschweig, Spielmannstrasse 7, 38106, Braunschweig, Germany
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355
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Chapter Six - The Ubiquitin Network in the Control of EGFR Endocytosis and Signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 141:225-76. [DOI: 10.1016/bs.pmbts.2016.03.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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356
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Madu UL, Ogundeji AO, Mochochoko BM, Pohl CH, Albertyn J, Swart CW, Allwood JW, Southam AD, Dunn WB, May RC, Sebolai OM. Cryptococcal 3-Hydroxy Fatty Acids Protect Cells Against Amoebal Phagocytosis. Front Microbiol 2015; 6:1351. [PMID: 26696972 PMCID: PMC4673343 DOI: 10.3389/fmicb.2015.01351] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/16/2015] [Indexed: 11/21/2022] Open
Abstract
We previously reported on a 3-hydroxy fatty acid that is secreted via cryptococcal capsular protuberances - possibly to promote pathogenesis and survival. Thus, we investigated the role of this molecule in mediating the fate of Cryptococcus (C.) neoformans and the related species C. gattii when predated upon by amoebae. We show that this molecule protects cells against the phagocytic effects of amoebae. C. neoformans UOFS Y-1378 (which produces 3-hydroxy fatty acids) was less sensitive toward amoebae compared to C. neoformans LMPE 046 and C. gattii R265 (both do not produce 3-hydroxy fatty acids) and addition of 3-hydroxy fatty acids to C. neoformans LMPE 046 and C. gattii R265 culture media, causes these strains to become more resistant to amoebal predation. Conversely, addition of aspirin (a 3-hydroxy fatty acid inhibitor) to C. neoformans UOFS Y-1378 culture media made cells more susceptible to amoebae. Our data suggest that this molecule is secreted at a high enough concentration to effect intracellular signaling within amoeba, which in turn, promotes fungal survival.
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Affiliation(s)
- Uju L. Madu
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free StateBloemfontein, South Africa
| | - Adepemi O. Ogundeji
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free StateBloemfontein, South Africa
| | - Bonang M. Mochochoko
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free StateBloemfontein, South Africa
| | - Carolina H. Pohl
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free StateBloemfontein, South Africa
| | - Jacobus Albertyn
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free StateBloemfontein, South Africa
| | - Chantel W. Swart
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free StateBloemfontein, South Africa
| | | | | | - Warwick B. Dunn
- School of Biosciences, University of BirminghamBirmingham, UK
| | - Robin C. May
- School of Biosciences, University of BirminghamBirmingham, UK
- Institute of Microbiology and Infection and the School of Biosciences, University of BirminghamBirmingham, UK
| | - Olihile M. Sebolai
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free StateBloemfontein, South Africa
- Institute of Microbiology and Infection and the School of Biosciences, University of BirminghamBirmingham, UK
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357
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Flannagan RS, Heit B, Heinrichs DE. Antimicrobial Mechanisms of Macrophages and the Immune Evasion Strategies of Staphylococcus aureus. Pathogens 2015; 4:826-68. [PMID: 26633519 PMCID: PMC4693167 DOI: 10.3390/pathogens4040826] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 11/17/2015] [Accepted: 11/24/2015] [Indexed: 12/21/2022] Open
Abstract
Habitually professional phagocytes, including macrophages, eradicate microbial invaders from the human body without overt signs of infection. Despite this, there exist select bacteria that are professional pathogens, causing significant morbidity and mortality across the globe and Staphylococcus aureus is no exception. S. aureus is a highly successful pathogen that can infect virtually every tissue that comprises the human body causing a broad spectrum of diseases. The profound pathogenic capacity of S. aureus can be attributed, in part, to its ability to elaborate a profusion of bacterial effectors that circumvent host immunity. Macrophages are important professional phagocytes that contribute to both the innate and adaptive immune response, however from in vitro and in vivo studies, it is evident that they fail to eradicate S. aureus. This review provides an overview of the antimicrobial mechanisms employed by macrophages to combat bacteria and describes the immune evasion strategies and some representative effectors that enable S. aureus to evade macrophage-mediated killing.
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Affiliation(s)
- Ronald S Flannagan
- Department of Microbiology and Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Bryan Heit
- Department of Microbiology and Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
- Centre for Human Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
| | - David E Heinrichs
- Department of Microbiology and Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
- Centre for Human Immunology, the University of Western Ontario, London, ON N6A 5C1, Canada.
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358
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Regulators and Effectors of Arf GTPases in Neutrophils. J Immunol Res 2015; 2015:235170. [PMID: 26609537 PMCID: PMC4644846 DOI: 10.1155/2015/235170] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/30/2015] [Indexed: 12/22/2022] Open
Abstract
Polymorphonuclear neutrophils (PMNs) are key innate immune cells that represent the first line of defence against infection. They are the first leukocytes to migrate from the blood to injured or infected sites. This process involves molecular mechanisms that coordinate cell polarization, delivery of receptors, and activation of integrins at the leading edge of migrating PMNs. These phagocytes actively engulf microorganisms or form neutrophil extracellular traps (NETs) to trap and kill pathogens with bactericidal compounds. Association of the NADPH oxidase complex at the phagosomal membrane for production of reactive oxygen species (ROS) and delivery of proteolytic enzymes into the phagosome initiate pathogen killing and removal. G protein-dependent signalling pathways tightly control PMN functions. In this review, we will focus on the small monomeric GTPases of the Arf family and their guanine exchange factors (GEFs) and GTPase activating proteins (GAPs) as components of signalling cascades regulating PMN responses. GEFs and GAPs are multidomain proteins that control cellular events in time and space through interaction with other proteins and lipids inside the cells. The number of Arf GAPs identified in PMNs is expanding, and dissecting their functions will provide important insights into the role of these proteins in PMN physiology.
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359
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Schlam D, Bagshaw RD, Freeman SA, Collins RF, Pawson T, Fairn GD, Grinstein S. Phosphoinositide 3-kinase enables phagocytosis of large particles by terminating actin assembly through Rac/Cdc42 GTPase-activating proteins. Nat Commun 2015; 6:8623. [PMID: 26465210 PMCID: PMC4634337 DOI: 10.1038/ncomms9623] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 09/11/2015] [Indexed: 02/06/2023] Open
Abstract
Phagocytosis is responsible for the elimination of particles of widely disparate sizes, from large fungi or effete cells to small bacteria. Though superficially similar, the molecular mechanisms involved differ: engulfment of large targets requires phosphoinositide 3-kinase (PI3K), while that of small ones does not. Here, we report that inactivation of Rac and Cdc42 at phagocytic cups is essential to complete internalization of large particles. Through a screen of 62 RhoGAP-family members, we demonstrate that ARHGAP12, ARHGAP25 and SH3BP1 are responsible for GTPase inactivation. Silencing these RhoGAPs impairs phagocytosis of large targets. The GAPs are recruited to large—but not small—phagocytic cups by products of PI3K, where they synergistically inactivate Rac and Cdc42. Remarkably, the prominent accumulation of phosphatidylinositol 3,4,5-trisphosphate characteristic of large-phagosome formation is less evident during phagocytosis of small targets, accounting for the contrasting RhoGAP distribution and the differential requirement for PI3K during phagocytosis of dissimilarly sized particles. Phagocytosis of large (but not small) particles requires PI 3-kinase activity. Here, Schlam et al. show that Rho GTPase-activating proteins are recruited to the phagocytic cup by products of PI 3-kinase, resulting in the local inactivation of Rac and Cdc42 and allowing for the completion of internalization of large particles.
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Affiliation(s)
- Daniel Schlam
- Division of Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G1X8.,Institute of Medical Science, University of Toronto, Faculty of Medicine, 1 King's College Circle, Toronto, Ontario, Canada M5S1A8
| | - Richard D Bagshaw
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G1X5
| | - Spencer A Freeman
- Division of Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G1X8
| | - Richard F Collins
- Division of Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G1X8
| | - Tony Pawson
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada M5G1X5
| | - Gregory D Fairn
- Institute of Medical Science, University of Toronto, Faculty of Medicine, 1 King's College Circle, Toronto, Ontario, Canada M5S1A8.,Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario, Canada M5B1T8
| | - Sergio Grinstein
- Division of Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G1X8.,Institute of Medical Science, University of Toronto, Faculty of Medicine, 1 King's College Circle, Toronto, Ontario, Canada M5S1A8.,Keenan Research Centre for Biomedical Science, St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario, Canada M5B1T8
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360
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Bi WJ, Li DX, Xu YH, Xu S, Li J, Zhao XF, Wang JX. Scavenger receptor B protects shrimp from bacteria by enhancing phagocytosis and regulating expression of antimicrobial peptides. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2015; 51:10-21. [PMID: 25697802 DOI: 10.1016/j.dci.2015.02.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/04/2015] [Accepted: 02/05/2015] [Indexed: 06/04/2023]
Abstract
Scavenger receptors (SRs) are involved in innate immunity through recognizing pathogen-associated molecular patterns (PAMPs) and in pathogenesis of diseases through interactions with damage-associated molecular patterns (DAMPs). The roles of SRs in invertebrate innate immunity still need to be elucidated. Here we identify a class B scavenger receptor from kuruma shrimp, Marsupenaeus japonicus, designated MjSR-B1. The recombinant MjSR-B1 agglutinated bacteria in a calcium dependent manner and bound lipopolysaccharide and lipoteichoic acid. After knockdown of MjSR-B1, both the bacterial clearance and phagocytotic ability of M. japonicus against V. anguillarum and S. aureus were impaired, and several phagocytosis related genes were downregulated. The expression levels of antimicrobial peptides were also downregulated. Overexpression of MjSR-B1 led to enhanced bacterial clearance, phagocytosis rate and upregulation of phagocytosis-related and antimicrobial peptide genes. However, overexpression of mutant MjSR-B1ΔC, which lacks the carboxyl tail of MjSR-B1, had none of these effects. Our results indicate that MjSR-B1 can protect shrimp from bacteria by promoting phagocytosis and by enhancing the expression of antimicrobial peptides.
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Affiliation(s)
- Wen-Jie Bi
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Dian-Xiang Li
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan 250022, China
| | - Yi-Hui Xu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Sen Xu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Jing Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Xiao-Fan Zhao
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China
| | - Jin-Xing Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, China.
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361
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Affiliation(s)
- Gwendalyn J Randolph
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
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362
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Lillico DME, Zwozdesky MA, Pemberton JG, Deutscher JM, Jones LO, Chang JP, Stafford JL. Teleost leukocyte immune-type receptors activate distinct phagocytic modes for target acquisition and engulfment. J Leukoc Biol 2015; 98:235-48. [DOI: 10.1189/jlb.2a0215-039rr] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/15/2015] [Indexed: 12/22/2022] Open
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363
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Proag A, Bouissou A, Mangeat T, Voituriez R, Delobelle P, Thibault C, Vieu C, Maridonneau-Parini I, Poincloux R. Working together: spatial synchrony in the force and actin dynamics of podosome first neighbors. ACS NANO 2015; 9:3800-3813. [PMID: 25791988 DOI: 10.1021/nn506745r] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Podosomes are mechanosensitive adhesion cell structures that are capable of applying protrusive forces onto the extracellular environment. We have recently developed a method dedicated to the evaluation of the nanoscale forces that podosomes generate to protrude into the extracellular matrix. It consists in measuring by atomic force microscopy (AFM) the nanometer deformations produced by macrophages on a compliant Formvar membrane and has been called protrusion force microscopy (PFM). Here we perform time-lapse PFM experiments and investigate spatial correlations of force dynamics between podosome pairs. We use an automated procedure based on finite element simulations that extends the analysis of PFM experimental data to take into account podosome architecture and organization. We show that protrusion force varies in a synchronous manner for podosome first neighbors, a result that correlates with phase synchrony of core F-actin temporal oscillations. This dynamic spatial coordination between podosomes suggests a short-range interaction that regulates their mechanical activity.
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Affiliation(s)
- Amsha Proag
- †IPBS (Institut de Pharmacologie et de Biologie Structurale), UMR CNRS 5089, 205 route de Narbonne, F-31077 Toulouse, France
- ‡UPS, Université de Toulouse, F-31400 Toulouse, France
| | - Anaïs Bouissou
- †IPBS (Institut de Pharmacologie et de Biologie Structurale), UMR CNRS 5089, 205 route de Narbonne, F-31077 Toulouse, France
- ‡UPS, Université de Toulouse, F-31400 Toulouse, France
| | - Thomas Mangeat
- ‡UPS, Université de Toulouse, F-31400 Toulouse, France
- §CNRS, LBCMCP, 118 route de Narbonne, F-31400 Toulouse, France
| | - Raphaël Voituriez
- ⊥UPMC, Laboratoire Jean Perrin, FRE 3231 CNRS-UPMC, 4 place Jussieu, F-75005 Paris, France
| | - Patrick Delobelle
- ∥FEMTO-ST, UMR CNRS 6174, Université de Franche Comté, 24 rue de l'Epitaphe, F-25000 Besançon, France
| | - Christophe Thibault
- #CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France
- ∇INSA, Université de Toulouse, F-31400 Toulouse, France
| | - Christophe Vieu
- #CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France
- ∇INSA, Université de Toulouse, F-31400 Toulouse, France
| | - Isabelle Maridonneau-Parini
- †IPBS (Institut de Pharmacologie et de Biologie Structurale), UMR CNRS 5089, 205 route de Narbonne, F-31077 Toulouse, France
- ‡UPS, Université de Toulouse, F-31400 Toulouse, France
| | - Renaud Poincloux
- †IPBS (Institut de Pharmacologie et de Biologie Structurale), UMR CNRS 5089, 205 route de Narbonne, F-31077 Toulouse, France
- ‡UPS, Université de Toulouse, F-31400 Toulouse, France
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364
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Santos AS, Finlay BB. Bringing down the host: enteropathogenic and enterohaemorrhagic Escherichia coli effector-mediated subversion of host innate immune pathways. Cell Microbiol 2015; 17:318-32. [PMID: 25588886 DOI: 10.1111/cmi.12412] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/17/2014] [Accepted: 12/22/2014] [Indexed: 12/14/2022]
Abstract
Enteric bacterial pathogens commonly use a type III secretion system (T3SS) to successfully infect intestinal epithelial cells and survive and proliferate in the host. Enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC; EHEC) colonize the human intestinal mucosa, form characteristic histological lesions on the infected epithelium and require the T3SS for full virulence. T3SS effectors injected into host cells subvert cellular pathways to execute a variety of functions within infected host cells. The EPEC and EHEC effectors that subvert innate immune pathways--specifically those involved in phagocytosis, host cell survival, apoptotic cell death and inflammatory signalling--are all required to cause disease. These processes are reviewed within, with a focus on recent work that has provided insights into the functions and host cell targets of these effectors.
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Affiliation(s)
- Andrew S Santos
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, BC, Canada; Michael Smith Laboratories, The University of British Columbia, Vancouver, BC, Canada
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