51
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Dovey CM, Diep J, Clarke BP, Hale AT, McNamara DE, Guo H, Brown NW, Cao JY, Grace CR, Gough PJ, Bertin J, Dixon SJ, Fiedler D, Mocarski ES, Kaiser WJ, Moldoveanu T, York JD, Carette JE. MLKL Requires the Inositol Phosphate Code to Execute Necroptosis. Mol Cell 2018; 70:936-948.e7. [PMID: 29883610 PMCID: PMC5994928 DOI: 10.1016/j.molcel.2018.05.010] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/12/2018] [Accepted: 05/07/2018] [Indexed: 01/28/2023]
Abstract
Necroptosis is an important form of lytic cell death triggered by injury and infection, but whether mixed lineage kinase domain-like (MLKL) is sufficient to execute this pathway is unknown. In a genetic selection for human cell mutants defective for MLKL-dependent necroptosis, we identified mutations in IPMK and ITPK1, which encode inositol phosphate (IP) kinases that regulate the IP code of soluble molecules. We show that IP kinases are essential for necroptosis triggered by death receptor activation, herpesvirus infection, or a pro-necrotic MLKL mutant. In IP kinase mutant cells, MLKL failed to oligomerize and localize to membranes despite proper receptor-interacting protein kinase-3 (RIPK3)-dependent phosphorylation. We demonstrate that necroptosis requires IP-specific kinase activity and that a highly phosphorylated product, but not a lowly phosphorylated precursor, potently displaces the MLKL auto-inhibitory brace region. These observations reveal control of MLKL-mediated necroptosis by a metabolite and identify a key molecular mechanism underlying regulated cell death.
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Affiliation(s)
- Cole M Dovey
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jonathan Diep
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Bradley P Clarke
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Andrew T Hale
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Dan E McNamara
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hongyan Guo
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Sciences Center, San Antonio, TX 78229, USA
| | - Nathaniel W Brown
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA; Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | | | - Christy R Grace
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Peter J Gough
- Host Defense Discovery Performance Unit, Infectious Diseases Therapy Area Unit, GlaxoSmithKline, Collegeville, PA 19426, USA
| | - John Bertin
- Pattern Recognition Receptor Discovery Performance Unit, Immuno-Inflammation Therapeutic Area, GlaxoSmithKline, Collegeville, PA 19426, USA
| | - Scott J Dixon
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Edward S Mocarski
- Department of Microbiology and Immunology, Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - William J Kaiser
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Sciences Center, San Antonio, TX 78229, USA
| | - Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - John D York
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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52
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Zhang K, Riba A, Nietschke M, Torow N, Repnik U, Pütz A, Fulde M, Dupont A, Hensel M, Hornef M. Minimal SPI1-T3SS effector requirement for Salmonella enterocyte invasion and intracellular proliferation in vivo. PLoS Pathog 2018. [PMID: 29522566 PMCID: PMC5862521 DOI: 10.1371/journal.ppat.1006925] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Effector molecules translocated by the Salmonella pathogenicity island (SPI)1-encoded type 3 secretion system (T3SS) critically contribute to the pathogenesis of human Salmonella infection. They facilitate internalization by non-phagocytic enterocytes rendering the intestinal epithelium an entry site for infection. Their function in vivo has remained ill-defined due to the lack of a suitable animal model that allows visualization of intraepithelial Salmonella. Here, we took advantage of our novel neonatal mouse model and analyzed various bacterial mutants and reporter strains as well as gene deficient mice. Our results demonstrate the critical but redundant role of SopE2 and SipA for enterocyte invasion, prerequisite for transcriptional stimulation and mucosal translocation in vivo. In contrast, the generation of a replicative intraepithelial endosomal compartment required the cooperative action of SipA and SopE2 or SipA and SopB but was independent of SopA or host MyD88 signaling. Intraepithelial growth had no critical influence on systemic spread. Our results define the role of SPI1-T3SS effector molecules during enterocyte invasion and intraepithelial proliferation in vivo providing novel insight in the early course of Salmonella infection. Non-typhoidal Salmonella represent a major causative agent of gastroenteritis worldwide. Hallmark of the pathogenesis is their ability to actively invade the intestinal epithelium by virtue of their type 3 secretion system that delivers bacterial virulence factors directly into the host cell cytosol. The role of these virulence factors during enterocyte entry and intraepithelial growth has only been investigated in vitro since the previously established in vivo models in small animals did not allow visualization of intraepithelial Salmonella. However, immortalized cell lines lack the overlaying mucus layer, final cell lineage differentiation, apical-basolateral polarization as well as continuous migration along the crypt villus axis and thus the role of virulence factors during the Salmonella infection in vivo has remained largely undefined. Here, we took advantage of our novel neonatal mouse infection model and for the first time systematically analyzed the importance of Salmonella virulence factors for enterocyte invasion and intraepithelial growth.
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Affiliation(s)
- Kaiyi Zhang
- Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
| | - Ambre Riba
- Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
| | - Monika Nietschke
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Natalia Torow
- Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
| | - Urska Repnik
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Andreas Pütz
- Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
| | - Marcus Fulde
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Aline Dupont
- Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
| | - Michael Hensel
- Division of Microbiology, University of Osnabrück, Osnabrück, Germany
| | - Mathias Hornef
- Institute of Medical Microbiology, RWTH University Hospital, Aachen, Germany
- * E-mail:
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53
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Cooper KG, Chong A, Starr T, Finn CE, Steele-Mortimer O. Predictable, Tunable Protein Production in Salmonella for Studying Host-Pathogen Interactions. Front Cell Infect Microbiol 2017; 7:475. [PMID: 29201859 PMCID: PMC5696353 DOI: 10.3389/fcimb.2017.00475] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 10/31/2017] [Indexed: 12/30/2022] Open
Abstract
Here we describe the use of synthetic genetic elements to improve the predictability and tunability of episomal protein production in Salmonella. We used a multi-pronged approach, in which a series of variable-strength synthetic promoters were combined with a synthetic transcriptional terminator, and plasmid copy number variation. This yielded a series of plasmids that drive uniform production of fluorescent and endogenous proteins, over a wide dynamic range. We describe several examples where this system is used to fine-tune constitutive expression in Salmonella, providing an efficient means to titrate out toxic effects of protein production.
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Affiliation(s)
- Kendal G Cooper
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Audrey Chong
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Tregei Starr
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Ciaran E Finn
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Olivia Steele-Mortimer
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
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54
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Ghosh S, O'Connor TJ. Beyond Paralogs: The Multiple Layers of Redundancy in Bacterial Pathogenesis. Front Cell Infect Microbiol 2017; 7:467. [PMID: 29188194 PMCID: PMC5694747 DOI: 10.3389/fcimb.2017.00467] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 10/20/2017] [Indexed: 01/06/2023] Open
Abstract
Redundancy has been referred to as a state of no longer being needed or useful. Microbiologists often theorize that the only case of true redundancy in a haploid organism would be a recent gene duplication event, prior to divergence through selective pressure. However, a growing number of examples exist where an organism encodes two genes that appear to perform the same function. For example, many pathogens translocate multiple effector proteins into hosts. While disruption of individual effector genes does not result in a discernable phenotype, deleting genes in combination impairs pathogenesis: this has been described as redundancy. In many cases, this apparent redundancy could be due to limitations of laboratory models of pathogenesis that do not fully recapitulate the disease process. Alternatively, it is possible that the selective advantage achieved by this perceived redundancy is too subtle to be measured in the laboratory. Moreover, there are numerous possibilities for different types of redundancy. The most common and recognized form of redundancy is functional redundancy whereby two proteins have similar biochemical activities and substrate specificities allowing each one to compensate in the absence of the other. However, redundancy can also exist between seemingly unrelated proteins that manipulate the same or complementary host cell pathways. In this article, we outline 5 types of redundancy in pathogenesis: molecular, target, pathway, cellular process, and system redundancy that incorporate the biochemical activities, the host target specificities and the impact of effector function on the pathways and cellular process they modulate. For each type of redundancy, we provide examples from Legionella pathogenesis as this organism employs over 300 secreted virulence proteins and loss of individual proteins rarely impacts intracellular growth. We also discuss selective pressures that drive the maintenance of redundant mechanisms, the current methods used to resolve redundancy and features that distinguish between redundant and non-redundant virulence mechanisms.
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Affiliation(s)
- Soma Ghosh
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Tamara J O'Connor
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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55
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Zhang K, Griffiths G, Repnik U, Hornef M. Seeing is understanding: Salmonella's way to penetrate the intestinal epithelium. Int J Med Microbiol 2017; 308:97-106. [PMID: 28939439 DOI: 10.1016/j.ijmm.2017.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/06/2017] [Accepted: 09/11/2017] [Indexed: 02/06/2023] Open
Abstract
The molecular processes that govern host-microbial interaction illustrate not only the sophisticated and multifaceted mechanisms that protect the host from infection, but also the elaborated features of microbial pathogens that have evolved to overcome or evade the host's immune system. Here we focus on Salmonella that like other enteric pathogens must overcome the intestinal mucosal immune system, a surface constantly on alert and evolved to restrict the enteric microbiota. We discuss the initial step of Salmonella infection, the penetration of the intestinal epithelial barrier and the models used to study this fascinating aspect of microbial pathogenesis.
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Affiliation(s)
- Kaiyi Zhang
- Institute of Medical Microbiology, RWTH University Hospital Aachen, Aachen, Germany
| | | | - Urska Repnik
- Department of Biosciences, University of Oslo, Oslo, Norway.
| | - Mathias Hornef
- Institute of Medical Microbiology, RWTH University Hospital Aachen, Aachen, Germany.
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56
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Young AM, Palmer AE. Methods to Illuminate the Role of Salmonella Effector Proteins during Infection: A Review. Front Cell Infect Microbiol 2017; 7:363. [PMID: 28848721 PMCID: PMC5554337 DOI: 10.3389/fcimb.2017.00363] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 07/27/2017] [Indexed: 12/19/2022] Open
Abstract
Intracellular bacterial pathogens like Salmonella enterica use secretion systems, such as the Type III Secretion System, to deliver virulence factors into host cells in order to invade and colonize these cells. Salmonella virulence factors include a suite of effector proteins that remodel the host cell to facilitate bacterial internalization, replication, and evasion of host immune surveillance. A number of diverse and innovative approaches have been used to identify and characterize the role of effector proteins during infection. Recent techniques for studying infection using single cell and animal models have illuminated the contribution of individual effector proteins in infection. This review will highlight the techniques applied to study Salmonella effector proteins during infection. It will describe how different approaches have revealed mechanistic details for effectors in manipulating host cellular processes including: the dynamics of effector translocation into host cells, cytoskeleton reorganization, membrane trafficking, gene regulation, and autophagy.
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Affiliation(s)
- Alexandra M Young
- Department of Chemistry and Biochemistry, BioFrontiers Institute, University of Colorado BoulderBoulder, CO, United States
| | - Amy E Palmer
- Department of Chemistry and Biochemistry, BioFrontiers Institute, University of Colorado BoulderBoulder, CO, United States
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57
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Hume PJ, Singh V, Davidson AC, Koronakis V. Swiss Army Pathogen: The Salmonella Entry Toolkit. Front Cell Infect Microbiol 2017; 7:348. [PMID: 28848711 PMCID: PMC5552672 DOI: 10.3389/fcimb.2017.00348] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/21/2017] [Indexed: 02/04/2023] Open
Abstract
Salmonella causes disease in humans and animals ranging from mild self-limiting gastroenteritis to potentially life-threatening typhoid fever. Salmonellosis remains a considerable cause of morbidity and mortality globally, and hence imposes a huge socio-economic burden worldwide. A key property of all pathogenic Salmonella strains is the ability to invade non-phagocytic host cells. The major determinant of this invasiveness is a Type 3 Secretion System (T3SS), a molecular syringe that injects virulence effector proteins directly into target host cells. These effectors cooperatively manipulate multiple host cell signaling pathways to drive pathogen internalization. Salmonella does not only rely on these injected effectors, but also uses several other T3SS-independent mechanisms to gain entry into host cells. This review summarizes our current understanding of the methods used by Salmonella for cell invasion, with a focus on the host signaling networks that must be coordinately exploited for the pathogen to achieve its goal.
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Affiliation(s)
- Peter J Hume
- Department of Pathology, University of CambridgeCambridge, United Kingdom
| | - Vikash Singh
- Department of Pathology, University of CambridgeCambridge, United Kingdom
| | - Anthony C Davidson
- Department of Pathology, University of CambridgeCambridge, United Kingdom
| | - Vassilis Koronakis
- Department of Pathology, University of CambridgeCambridge, United Kingdom
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58
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Abstract
Intracellular bacterial pathogens survive and replicate within specialized eukaryotic cell organelles. To establish their intracellular niches these pathogens have adopted sophisticated strategies to control intracellular membrane trafficking. Since Rab-family GTPases are critical regulators of endocytic and secretory membrane trafficking events, many intracellular pathogens have evolved specific mechanisms to modulate or hijack Rab GTPases dynamics and trafficking functions. One such strategy is the delivery of bacterial effectors through specialized machines to specifically target Rab GTPases. Some of these effectors functionally mimic host proteins that regulate the Rab GTP cycle, while others regulate Rabs proteins through their post-translation modifications or proteolysis. In this review, we examine how the localization and function of Rab-family GTPases are altered during infection with 3 well-studied intracellular bacterial pathogens, Mycobacterium tuberculosis, Salmonella enterica and Legionella pneumophila. We also discuss recent findings about specific mechanisms by which these intracellular pathogens target this protein family.
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Affiliation(s)
- Stefania Spanò
- a Institute of Medical Sciences, University of Aberdeen , Foresterhill , Aberdeen , UK
| | - Jorge E Galán
- b Department of Microbial Pathogenesis , Yale University School of Medicine , New Haven , CT , USA
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59
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Lin YH, Machner MP. Exploitation of the host cell ubiquitin machinery by microbial effector proteins. J Cell Sci 2017; 130:1985-1996. [PMID: 28476939 PMCID: PMC5482977 DOI: 10.1242/jcs.188482] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Pathogenic bacteria are in a constant battle for survival with their host. In order to gain a competitive edge, they employ a variety of sophisticated strategies that allow them to modify conserved host cell processes in ways that favor bacterial survival and growth. Ubiquitylation, the covalent attachment of the small modifier ubiquitin to target proteins, is such a pathway. Ubiquitylation profoundly alters the fate of a myriad of cellular proteins by inducing changes in their stability or function, subcellular localization or interaction with other proteins. Given the importance of ubiquitylation in cell development, protein homeostasis and innate immunity, it is not surprising that this post-translational modification is exploited by a variety of effector proteins from microbial pathogens. Here, we highlight recent advances in our understanding of the many ways microbes take advantage of host ubiquitylation, along with some surprising deviations from the canonical theme. The lessons learned from the in-depth analyses of these host-pathogen interactions provide a fresh perspective on an ancient post-translational modification that we thought was well understood.This article is part of a Minifocus on Ubiquitin Regulation and Function. For further reading, please see related articles: 'Mechanisms of regulation and diversification of deubiquitylating enzyme function' by Pawel Leznicki and Yogesh Kulathu (J. Cell Sci.130, 1997-2006). 'Cell scientist to watch - Mads Gyrd-Hansen' (J. Cell Sci.130, 1981-1983).
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Affiliation(s)
- Yi-Han Lin
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Matthias P Machner
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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60
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Visualization and characterization of individual type III protein secretion machines in live bacteria. Proc Natl Acad Sci U S A 2017; 114:6098-6103. [PMID: 28533372 PMCID: PMC5468683 DOI: 10.1073/pnas.1705823114] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Type III protein secretion machines have evolved to deliver bacterially encoded effector proteins into eukaryotic cells. Although electron microscopy has provided a detailed view of these machines in isolation or fixed samples, little is known about their organization in live bacteria. Here we report the visualization and characterization of the Salmonella type III secretion machine in live bacteria by 2D and 3D single-molecule switching superresolution microscopy. This approach provided access to transient components of this machine, which previously could not be analyzed. We determined the subcellular distribution of individual machines, the stoichiometry of the different components of this machine in situ, and the spatial distribution of the substrates of this machine before secretion. Furthermore, by visualizing this machine in Salmonella mutants we obtained major insights into the machine's assembly. This study bridges a major resolution gap in the visualization of this nanomachine and may serve as a paradigm for the examination of other bacterially encoded molecular machines.
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61
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Tasmin R, Hasan NA, Grim CJ, Grant A, Choi SY, Alam MS, Bell R, Cavanaugh C, Balan KV, Babu US, Parveen S. Genotypic and phenotypic characterization of multidrug resistant Salmonella Typhimurium and Salmonella Kentucky strains recovered from chicken carcasses. PLoS One 2017; 12:e0176938. [PMID: 28481935 PMCID: PMC5421757 DOI: 10.1371/journal.pone.0176938] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 04/19/2017] [Indexed: 01/18/2023] Open
Abstract
Salmonella Typhimurium is the leading cause of human non-typhoidal gastroenteritis in the US. S. Kentucky is one the most commonly recovered serovars from commercially processed poultry carcasses. This study compared the genotypic and phenotypic properties of two Salmonella enterica strains Typhimurium (ST221_31B) and Kentucky (SK222_32B) recovered from commercially processed chicken carcasses using whole genome sequencing, phenotype characterizations and an intracellular killing assay. Illumina MiSeq platform was used for sequencing of two Salmonella genomes. Phylogenetic analysis employing homologous alignment of a 1,185 non-duplicated protein-coding gene in the Salmonella core genome demonstrated fully resolved bifurcating patterns with varying levels of diversity that separated ST221_31B and SK222_32B genomes into distinct monophyletic serovar clades. Single nucleotide polymorphism (SNP) analysis identified 2,432 (ST19) SNPs within 13 Typhimurium genomes including ST221_31B representing Sequence Type ST19 and 650 (ST152) SNPs were detected within 13 Kentucky genomes including SK222_32B representing Sequence Type ST152. In addition to serovar-specific conserved coding sequences, the genomes of ST221_31B and SK222_32B harbor several genomic regions with significant genetic differences. These included phage and phage-like elements, carbon utilization or transport operons, fimbriae operons, putative membrane associated protein-encoding genes, antibiotic resistance genes, siderophore operons, and numerous hypothetical protein-encoding genes. Phenotype microarray results demonstrated that ST221_31B is capable of utilizing certain carbon compounds more efficiently as compared to SK222_3B; namely, 1,2-propanediol, M-inositol, L-threonine, α-D-lactose, D-tagatose, adonitol, formic acid, acetoacetic acid, and L-tartaric acid. ST221_31B survived for 48 h in macrophages, while SK222_32B was mostly eliminated. Further, a 3-fold growth of ST221_31B was observed at 24 hours post-infection in chicken granulosa cells while SK222_32B was unable to replicate in these cells. These results suggest that Salmonella Typhimurium can survive host defenses better and could be more invasive than Salmonella Kentucky and provide some insights into the genomic determinants responsible for these differences.
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Affiliation(s)
- Rizwana Tasmin
- Agriculture, Food and Resource Sciences, University of Maryland, Eastern Shore, Princess Anne, Maryland, United States of America
| | - Nur A. Hasan
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, Maryland, United States of America
- CosmosID Inc., Rockville, Maryland, United States of America
| | - Christopher J. Grim
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, Laurel, Maryland, United States of America
| | - Ar’Quette Grant
- Agriculture, Food and Resource Sciences, University of Maryland, Eastern Shore, Princess Anne, Maryland, United States of America
| | - Seon Young Choi
- CosmosID Inc., Rockville, Maryland, United States of America
| | - M. Samiul Alam
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, Laurel, Maryland, United States of America
| | - Rebecca Bell
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, Maryland, United States of America
| | - Christopher Cavanaugh
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, Laurel, Maryland, United States of America
| | - Kannan V. Balan
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, Laurel, Maryland, United States of America
| | - Uma S. Babu
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, Laurel, Maryland, United States of America
| | - Salina Parveen
- Agriculture, Food and Resource Sciences, University of Maryland, Eastern Shore, Princess Anne, Maryland, United States of America
- * E-mail:
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62
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Finn CE, Chong A, Cooper KG, Starr T, Steele-Mortimer O. A second wave of Salmonella T3SS1 activity prolongs the lifespan of infected epithelial cells. PLoS Pathog 2017; 13:e1006354. [PMID: 28426838 PMCID: PMC5413073 DOI: 10.1371/journal.ppat.1006354] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 05/02/2017] [Accepted: 04/14/2017] [Indexed: 11/19/2022] Open
Abstract
Type III secretion system 1 (T3SS1) is used by the enteropathogen Salmonella enterica serovar Typhimurium to establish infection in the gut. Effector proteins translocated by this system across the plasma membrane facilitate invasion of intestinal epithelial cells. One such effector, the inositol phosphatase SopB, contributes to invasion and mediates activation of the pro-survival kinase Akt. Following internalization, some bacteria escape from the Salmonella-containing vacuole into the cytosol and there is evidence suggesting that T3SS1 is expressed in this subpopulation. Here, we investigated the post-invasion role of T3SS1, using SopB as a model effector. In cultured epithelial cells, SopB-dependent Akt phosphorylation was observed at two distinct stages of infection: during and immediately after invasion, and later during peak cytosolic replication. Single cell analysis revealed that cytosolic Salmonella deliver SopB via T3SS1. Although intracellular replication was unaffected in a SopB deletion mutant, cells infected with ΔsopB demonstrated a lack of Akt phosphorylation, earlier time to death, and increased lysis. When SopB expression was induced specifically in cytosolic Salmonella, these effects were restored to levels observed in WT infected cells, indicating that the second wave of SopB protects this infected population against cell death via Akt activation. Thus, T3SS1 has two, temporally distinct roles during epithelial cell colonization. Additionally, we found that delivery of SopB by cytosolic bacteria was translocon-independent, in contrast to canonical effector translocation across eukaryotic membranes, which requires formation of a translocon pore. This mechanism was also observed for another T3SS1 effector, SipA. These findings reveal the functional and mechanistic adaptability of a T3SS that can be harnessed in different microenvironments.
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Affiliation(s)
- Ciaran E. Finn
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Audrey Chong
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Kendal G. Cooper
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Tregei Starr
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Olivia Steele-Mortimer
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
- * E-mail:
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63
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Odendall C, Kagan JC. Activation and pathogenic manipulation of the sensors of the innate immune system. Microbes Infect 2017; 19:229-237. [PMID: 28093320 PMCID: PMC6697111 DOI: 10.1016/j.micinf.2017.01.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/06/2017] [Indexed: 12/13/2022]
Abstract
The innate immune system detects the presence of microbes through different families of pattern-recognition receptors (PRRs). PRRs detect pathogens of all origins and trigger signaling events that activate innate and adaptive immunity. These events need to be tightly regulated in order to ensure optimal activation when required, and minimal signaling in the absence of microbial encounters. This regulation is achieved, at least in part, through the precise subcellular positioning of receptors and downstream signaling proteins. Consequently, mislocalization of these proteins inhibits innate immune pathways, and pathogens have evolved to alter host protein localization as a strategy to evade immune detection. This review describes the importance of subcellular localization of various PRR families and their adaptors, and highlights pathogenic immune evasion strategies that operate by altering immune protein localization.
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Affiliation(s)
- Charlotte Odendall
- Department of Infectious Diseases, King's College London, London SE1 9RT, UK
| | - Jonathan C Kagan
- Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, MA 02115, USA.
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MYO6 is targeted by Salmonella virulence effectors to trigger PI3-kinase signaling and pathogen invasion into host cells. Proc Natl Acad Sci U S A 2017; 114:3915-3920. [PMID: 28348208 DOI: 10.1073/pnas.1616418114] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To establish infections, Salmonella injects virulence effectors that hijack the host actin cytoskeleton and phosphoinositide signaling to drive pathogen invasion. How effectors reprogram the cytoskeleton network remains unclear. By reconstituting the activities of the Salmonella effector SopE, we recapitulated Rho GTPase-driven actin polymerization at model phospholipid membrane bilayers in cell-free extracts and identified the network of Rho-recruited cytoskeleton proteins. Knockdown of network components revealed a key role for myosin VI (MYO6) in Salmonella invasion. SopE triggered MYO6 localization to invasion foci, and SopE-mediated activation of PAK recruited MYO6 to actin-rich membranes. We show that the virulence effector SopB requires MYO6 to regulate the localization of PIP3 and PI(3)P phosphoinositides and Akt activation. SopE and SopB target MYO6 to coordinate phosphoinositide production at invasion foci, facilitating the recruitment of cytoskeleton adaptor proteins to mediate pathogen uptake.
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65
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Mechanisms of Horizontal Cell-to-Cell Transfer of Wolbachia spp. in Drosophila melanogaster. Appl Environ Microbiol 2017; 83:AEM.03425-16. [PMID: 28087534 DOI: 10.1128/aem.03425-16] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/10/2017] [Indexed: 12/18/2022] Open
Abstract
Wolbachia is an intracellular endosymbiont present in most arthropod and filarial nematode species. Transmission between hosts is primarily vertical, taking place exclusively through the female germ line, although horizontal transmission has also been documented. The results of several studies indicate that Wolbachia spp. can undergo transfer between somatic and germ line cells during nematode development and in adult flies. However, the mechanisms underlying horizontal cell-to-cell transfer remain largely unexplored. Here, we establish a tractable system for probing horizontal transfer of Wolbachia cells between Drosophila melanogaster cells in culture using fluorescence in situ hybridization (FISH). First, we show that horizontal transfer is independent of cell-to-cell contact and can efficiently take place through the culture medium within hours. Further, we demonstrate that efficient transfer utilizes host cell phagocytic and clathrin/dynamin-dependent endocytic machinery. Lastly, we provide evidence that this process is conserved between species, showing that horizontal transfer from mosquito to Drosophila cells takes place in a similar fashion. Altogether, our results indicate that Wolbachia utilizes host internalization machinery during infection, and this mechanism is conserved across insect species.IMPORTANCE Our work has broad implications for the control and treatment of tropical diseases. Wolbachia can confer resistance against a variety of human pathogens in mosquito vectors. Elucidating the mechanisms of horizontal transfer will be useful for efforts to more efficiently infect nonnatural insect hosts with Wolbachia as a biological control agent. Further, as Wolbachia is essential for the survival of filarial nematodes, understanding horizontal transfer might provide new approaches to treating human infections by targeting Wolbachia Finally, this work provides a key first step toward the genetic manipulation of Wolbachia.
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66
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Spanò S, Gao X, Hannemann S, Lara-Tejero M, Galán JE. A Bacterial Pathogen Targets a Host Rab-Family GTPase Defense Pathway with a GAP. Cell Host Microbe 2016; 19:216-26. [PMID: 26867180 DOI: 10.1016/j.chom.2016.01.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 12/24/2015] [Accepted: 01/19/2016] [Indexed: 12/21/2022]
Abstract
Cell-autonomous defense mechanisms are potent strategies that protect individual cells against intracellular pathogens. The Rab-family GTPase Rab32 was previously shown to restrict the intracellular human pathogen Salmonella Typhi, but its potential broader role in antimicrobial defense remains unknown. We show that Rab32 represents a general cell-autonomous, antimicrobial defense that is counteracted by two Salmonella effectors. Mice lacking Rab-32 or its nucleotide exchange factor BLOC-3 are permissive to S. Typhi infection and exhibit increased susceptibility to S. Typhimurium. S. Typhimurium counters this defense pathway by delivering two type III secretion effectors, SopD2, a Rab32 GAP, and GtgE, a specific Rab32 protease. An S. Typhimurium mutant strain lacking these two effectors exhibits markedly reduced virulence, which is fully restored in BLOC-3-deficient mice. These results demonstrate that a cell-autonomous, Rab32-dependent host defense pathway plays a central role in the defense against vacuolar pathogens and describe a mechanism evolved by a bacterial pathogen to counter it.
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Affiliation(s)
- Stefania Spanò
- Department of Microbial Pathogenesis, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
| | - Xiang Gao
- Department of Microbial Pathogenesis, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA
| | - Sebastian Hannemann
- Department of Microbial Pathogenesis, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA
| | - María Lara-Tejero
- Department of Microbial Pathogenesis, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA
| | - Jorge E Galán
- Department of Microbial Pathogenesis, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
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67
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Wang KC, Huang CH, Ding SM, Chen CK, Fang HW, Huang MT, Fang SB. Role of yqiC in the Pathogenicity of Salmonella and Innate Immune Responses of Human Intestinal Epithelium. Front Microbiol 2016; 7:1614. [PMID: 27777572 PMCID: PMC5056187 DOI: 10.3389/fmicb.2016.01614] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/27/2016] [Indexed: 01/12/2023] Open
Abstract
The yqiC gene of Salmonella enterica serovar Typhimurium (S. Typhimurium) regulates bacterial growth at different temperatures and mice survival after infection. However, the role of yqiC in bacterial colonization and host immunity remains unknown. We infected human LS174T, Caco-2, HeLa, and THP-1 cells with S. Typhimurium wild-type SL1344, its yqiC mutant, and its complemented strain. Bacterial colonization and internalization in the four cell lines significantly reduced on yqiC depletion. Post-infection production of interleukin-8 and human β-defensin-3 in LS174T cells significantly reduced because of yqiC deleted in S. Typhimurium. The phenotype of yqiC mutant exhibited few and short flagella, fimbriae on the cell surface, enhanced biofilm formation, upregulated type-1 fimbriae expression, and reduced bacterial motility. Type-1 fimbriae, flagella, SPI-1, and SPI-2 gene expression was quantified using real-time PCR. The data show that deletion of yqiC upregulated fimA and fimZ expression and downregulated flhD, fliZ, invA, and sseB expression. Furthermore, thin-layer chromatography and high-performance liquid chromatography revealed the absence of menaquinone in the yqiC mutant, thus validating the importance of yqiC in the bacterial electron transport chain. Therefore, YqiC can negatively regulate FimZ for type-1 fimbriae expression and manipulate the functions of its downstream virulence factors including flagella, SPI-1, and SPI-2 effectors.
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Affiliation(s)
- Ke-Chuan Wang
- Division of Pediatric Gastroenterology and Hepatology, Department of Pediatrics, Shuang Ho Hospital, Taipei Medical UniversityTaipei, Taiwan; Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical UniversityTaipei, Taiwan
| | - Chih-Hung Huang
- Graduate Institute of Biochemical and Biomedical Engineering, National Taipei University of Technology Taipei, Taiwan
| | - Shih-Min Ding
- Division of Pediatric Gastroenterology and Hepatology, Department of Pediatrics, Shuang Ho Hospital, Taipei Medical UniversityTaipei, Taiwan; Graduate Institute of Biochemical and Biomedical Engineering, National Taipei University of TechnologyTaipei, Taiwan
| | - Ching-Kuo Chen
- Graduate Institute of Biochemical and Biomedical Engineering, National Taipei University of Technology Taipei, Taiwan
| | - Hsu-Wei Fang
- Graduate Institute of Biochemical and Biomedical Engineering, National Taipei University of TechnologyTaipei, Taiwan; Institute of Biomedical Engineering and Nanomedicine - National Health Research InstitutesZhunan, Taiwan
| | - Ming-Te Huang
- Department of Surgery, Shuang Ho Hospital, Taipei Medical UniversityTaipei, Taiwan; Department of Surgery, School of Medicine, College of Medicine, Taipei Medical UniversityTaipei, Taiwan
| | - Shiuh-Bin Fang
- Division of Pediatric Gastroenterology and Hepatology, Department of Pediatrics, Shuang Ho Hospital, Taipei Medical UniversityTaipei, Taiwan; Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical UniversityTaipei, Taiwan
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68
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Andritschke D, Dilling S, Emmenlauer M, Welz T, Schmich F, Misselwitz B, Rämö P, Rottner K, Kerkhoff E, Wada T, Penninger JM, Beerenwinkel N, Horvath P, Dehio C, Hardt WD. A Genome-Wide siRNA Screen Implicates Spire1/2 in SipA-Driven Salmonella Typhimurium Host Cell Invasion. PLoS One 2016; 11:e0161965. [PMID: 27627128 PMCID: PMC5023170 DOI: 10.1371/journal.pone.0161965] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/15/2016] [Indexed: 12/20/2022] Open
Abstract
Salmonella Typhimurium (S. Tm) is a leading cause of diarrhea. The disease is triggered by pathogen invasion into the gut epithelium. Invasion is attributed to the SPI-1 type 3 secretion system (T1). T1 injects effector proteins into epithelial cells and thereby elicits rearrangements of the host cellular actin cytoskeleton and pathogen invasion. The T1 effector proteins SopE, SopB, SopE2 and SipA are contributing to this. However, the host cell factors contributing to invasion are still not completely understood. To address this question comprehensively, we used Hela tissue culture cells, a genome-wide siRNA library, a modified gentamicin protection assay and S. TmSipA, a sopBsopE2sopE mutant which strongly relies on the T1 effector protein SipA to invade host cells. We found that S. TmSipA invasion does not elicit membrane ruffles, nor promote the entry of non-invasive bacteria "in trans". However, SipA-mediated infection involved the SPIRE family of actin nucleators, besides well-established host cell factors (WRC, ARP2/3, RhoGTPases, COPI). Stage-specific follow-up assays and knockout fibroblasts indicated that SPIRE1 and SPIRE2 are involved in different steps of the S. Tm infection process. Whereas SPIRE1 interferes with bacterial binding, SPIRE2 influences intracellular replication of S. Tm. Hence, these two proteins might fulfill non-redundant functions in the pathogen-host interaction. The lack of co-localization hints to a short, direct interaction between S. Tm and SPIRE proteins or to an indirect effect.
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Affiliation(s)
- Daniel Andritschke
- Institute of Microbiology, Eidgenössische Technische Hochschule Zurich, CH-8093, Zurich, Switzerland
| | - Sabrina Dilling
- Institute of Microbiology, Eidgenössische Technische Hochschule Zurich, CH-8093, Zurich, Switzerland
| | | | - Tobias Welz
- Department of Neurology, University of Regensburg, DE- 93040, Regensburg, Germany
| | - Fabian Schmich
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule Zurich, CH-4058, Basel, Switzerland
- SIB Swiss Institute for Bioinformatics, 4058, Basel, Switzerland
| | - Benjamin Misselwitz
- Institute of Microbiology, Eidgenössische Technische Hochschule Zurich, CH-8093, Zurich, Switzerland
- Division of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, CH-8091, Zurich, Switzerland
| | - Pauli Rämö
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Klemens Rottner
- Zoological Institute, Technische Universität Braunschweig, D-38106, Braunschweig, Germany
- Department of Cell Biology, Helmholtz Centre for Infection Research, D-38124, Braunschweig, Germany
| | - Eugen Kerkhoff
- Department of Neurology, University of Regensburg, DE- 93040, Regensburg, Germany
| | - Teiji Wada
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), A-1030, Vienna, Austria
| | - Josef M. Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), A-1030, Vienna, Austria
| | - Niko Beerenwinkel
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule Zurich, CH-4058, Basel, Switzerland
- SIB Swiss Institute for Bioinformatics, 4058, Basel, Switzerland
| | - Peter Horvath
- Light Microscopy Center, Eidgenössische Technische Hochschule Zurich, CH-8093, Zurich, Switzerland
| | - Christoph Dehio
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Eidgenössische Technische Hochschule Zurich, CH-8093, Zurich, Switzerland
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69
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Subinhibitory concentrations of phloretin repress the virulence of Salmonella typhimurium and protect against Salmonella typhimurium infection. Antonie van Leeuwenhoek 2016; 109:1503-1512. [PMID: 27549210 DOI: 10.1007/s10482-016-0752-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 08/06/2016] [Indexed: 10/21/2022]
Abstract
Phloretin, a natural component of many fruits, exhibits anti-virulence effects and provides a new alternative to counter bacterial infection. The aim of this study was to determine the effect of subinhibitory concentrations of phloretin on the virulence of Salmonella typhimurium. At concentrations where growth of Salmonella was not inhibited, phloretin significantly inhibited bacteria biofilm formation and motility. Subinhibitory concentrations of phloretin repressed eight genes involved in the Salmonella pathogenicity island 1 and 3 genes involved in flagella production. Furthermore, subinhibitory concentrations of phloretin inhibited the adhesion and invasion of Salmonella in IEC-6 cells and reduced the LDH levels of S. typhimurium-infected IEC-6 cells. Additionally, phloretin significantly decreased the cecum bacterial loads of the mice infected with live S. typhimurium containing subinhibitory concentrations of phloretin by gavage. These results suggested that subinhibitory concentrations of phloretin attenuate the virulence of S. typhimurium and protect against S. typhimurium infection.
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70
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Kapetanovic R, Bokil NJ, Achard MES, Ong CLY, Peters KM, Stocks CJ, Phan MD, Monteleone M, Schroder K, Irvine KM, Saunders BM, Walker MJ, Stacey KJ, McEwan AG, Schembri MA, Sweet MJ. Salmonella employs multiple mechanisms to subvert the TLR-inducible zinc-mediated antimicrobial response of human macrophages. FASEB J 2016; 30:1901-12. [PMID: 26839376 DOI: 10.1096/fj.201500061] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 01/19/2016] [Indexed: 12/27/2022]
Abstract
We aimed to characterize antimicrobial zinc trafficking within macrophages and to determine whether the professional intramacrophage pathogen Salmonella enterica serovar Typhimurium (S Typhimurium) subverts this pathway. Using both Escherichia coli and S Typhimurium, we show that TLR signaling promotes the accumulation of vesicular zinc within primary human macrophages. Vesicular zinc is delivered to E. coli to promote microbial clearance, whereas S. Typhimurium evades this response via Salmonella pathogenicity island (SPI)-1. Even in the absence of SPI-1 and the zinc exporter ZntA, S Typhimurium resists the innate immune zinc stress response, implying the existence of additional host subversion mechanisms. We also demonstrate the combinatorial antimicrobial effects of zinc and copper, a pathway that S. Typhimurium again evades. Our use of complementary tools and approaches, including confocal microscopy, direct assessment of intramacrophage bacterial zinc stress responses, specific E. coli and S Typhimurium mutants, and inductively coupled plasma mass spectroscopy, has enabled carefully controlled characterization of this novel innate immune antimicrobial pathway. In summary, our study provides new insights at the cellular level into the well-documented effects of zinc in promoting host defense against infectious disease, as well as the complex host subversion strategies employed by S Typhimurium to combat this pathway.-Kapetanovic, R., Bokil, N. J., Achard, M. E. S., Ong, C.-L. Y., Peters, K. M., Stocks, C. J., Phan, M.-D., Monteleone, M., Schroder, K., Irvine, K. M., Saunders, B. M., Walker, M. J., Stacey, K. J., McEwan, A. G., Schembri, M. A., Sweet, M. J. Salmonella employs multiple mechanisms to subvert the TLR-inducible zinc-mediated antimicrobial response of human macrophages.
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Affiliation(s)
- Ronan Kapetanovic
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Australia; IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Nilesh J Bokil
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Australia; IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Maud E S Achard
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Cheryl-Lynn Y Ong
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Kate M Peters
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Claudia J Stocks
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Australia; IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Minh-Duy Phan
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Mercedes Monteleone
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Australia; IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Kate Schroder
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Australia; IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Katharine M Irvine
- IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Australia; School of Medicine, The University of Queensland, Woolloongabba, Australia; and
| | | | - Mark J Walker
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Katryn J Stacey
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Alastair G McEwan
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Australia; IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Australia; Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia;
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71
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Mechanisms of Salmonella Typhi Host Restriction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 915:283-94. [PMID: 27193549 DOI: 10.1007/978-3-319-32189-9_17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Salmonella enterica serovar Typhi (S. Typhi) is the cause of typhoid fever, a life-threatening bacterial infection that is very common in the developing world. Recent spread of antimicrobial resistant isolates of S. Typhi makes typhoid fever, a global public health risk. Despite being a common disease, still very little is known about the molecular mechanisms underlying typhoid fever and S. Typhi pathogenesis. In contrast to other Salmonellae, S. Typhi can only infect humans. The molecular bases of this human restriction are mostly unknown. Recent studies identified a novel pathway that contributes to S. Typhi human restriction and is required for killing S. Typhi in macrophages of nonsusceptible species. The small Rab GTPase Rab32 and its guanine nucleotide exchange factor BLOC-3 are the critical components of this pathway. These proteins were already well known as important regulators of intracellular membrane transport. In particular, they are central for the transport of enzymes that synthetize melanin in pigment cells. The recent findings that Rab32 and BLOC-3 are required for S. Typhi host restriction point out to a novel mechanism restricting the growth of bacterial pathogen, dependent on the transport of still unknown molecule(s) to the S. Typhi vacuole. The identification of this novel antimicrobial pathway constitutes a critical starting point to study molecular mechanisms killing bacterial pathogens and possibly identify novel antimicrobial molecules.
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72
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Kühn S, Mannherz HG. Actin: Structure, Function, Dynamics, and Interactions with Bacterial Toxins. Curr Top Microbiol Immunol 2016; 399:1-34. [PMID: 27848038 DOI: 10.1007/82_2016_45] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
Actin is one of the most abundant proteins in any eukaryotic cell and an indispensable component of the cytoskeleton. In mammalian organisms, six highly conserved actin isoforms can be distinguished, which differ by only a few amino acids. In non-muscle cells, actin polymerizes into actin filaments that form actin structures essential for cell shape stabilization, and participates in a number of motile activities like intracellular vesicle transport, cytokinesis, and also cell locomotion. Here, we describe the structure of monomeric and polymeric actin, the polymerization kinetics, and its regulation by actin-binding proteins. Probably due to its conserved nature and abundance, actin and its regulating factors have emerged as prefered targets of bacterial toxins and effectors, which subvert the host actin cytoskeleton to serve bacterial needs.
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Affiliation(s)
- Sonja Kühn
- Department of Cell Biology and Infection, Institut Pasteur, Paris, France
| | - Hans Georg Mannherz
- Department of Anatomy and Molecular Embryology, Ruhr-University, Bochum, Germany.
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73
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Stradal TEB, Costa SCP. Type III Secreted Virulence Factors Manipulating Signaling to Actin Dynamics. Curr Top Microbiol Immunol 2016; 399:175-199. [PMID: 27744505 DOI: 10.1007/82_2016_35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A key aspect of bacterial pathogenesis is the colonization and persistence within the host and, later on, its dissemination to new niches. During evolution, bacteria developed a myriad of virulence mechanisms to usurp the host's sophisticated defense mechanisms in order to establish their colonization niche. Elucidation of the highly dynamic and complex interactions between host and pathogens remains an important field of study. Here, we highlight the conserved manipulation of the actin cytoskeleton by some Gram-negative gastrointestinal pathogens, addressing the role of type III secreted bacterial GEFs at the different steps of pathogenesis. As a final topic, we review cytoskeleton dynamics induced by EPEC/EHEC strains for pedestal formation.
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Affiliation(s)
- Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Baunschweig, Germany.
| | - Sonia C P Costa
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Baunschweig, Germany
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74
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Van Nhieu GT, Romero S. Common Themes in Cytoskeletal Remodeling by Intracellular Bacterial Effectors. Handb Exp Pharmacol 2016; 235:207-235. [PMID: 27807696 DOI: 10.1007/164_2016_42] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Bacterial pathogens interact with various types of tissues to promote infection. Because it controls the formation of membrane extensions, adhesive processes, or the junction integrity, the actin cytoskeleton is a key target of pathogens during infection. We will highlight common and specific functions of the actin cytoskeleton during bacterial infections, by first reviewing the mechanisms of intracellular motility of invasive Shigella, Listeria, and Rickettsia. Through the models of EPEC/EHEC, Shigella, Salmonella, and Chlamydia spp., we will illustrate various strategies of diversion of actin cytoskeletal processes used by these bacteria to colonize or breach epithelial/endothelial barriers.
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Affiliation(s)
- Guy Tran Van Nhieu
- Equipe Communication Intercellulaire et Infections Microbiennes, Centre de Recherche Interdisciplinaire en Biologie (CIRB), Collège de France, 75005, Paris, France. .,Institut National de la Santé et de la Recherche Médicale U1050, 75005, Paris, France. .,Centre National de la Recherche Scientifique UMR7241, 75005, Paris, France. .,MEMOLIFE Laboratory of Excellence and Paris Science Lettre, 75005, Paris, France.
| | - Stéphane Romero
- Equipe Communication Intercellulaire et Infections Microbiennes, Centre de Recherche Interdisciplinaire en Biologie (CIRB), Collège de France, 75005, Paris, France.,Institut National de la Santé et de la Recherche Médicale U1050, 75005, Paris, France.,Centre National de la Recherche Scientifique UMR7241, 75005, Paris, France.,MEMOLIFE Laboratory of Excellence and Paris Science Lettre, 75005, Paris, France
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75
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Rosadini CV, Zanoni I, Odendall C, Green ER, Paczosa MK, Philip NH, Brodsky IE, Mecsas J, Kagan JC. A Single Bacterial Immune Evasion Strategy Dismantles Both MyD88 and TRIF Signaling Pathways Downstream of TLR4. Cell Host Microbe 2015; 18:682-93. [PMID: 26651944 PMCID: PMC4685476 DOI: 10.1016/j.chom.2015.11.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 09/09/2015] [Accepted: 11/17/2015] [Indexed: 01/10/2023]
Abstract
During bacterial infections, Toll-like receptor 4 (TLR4) signals through the MyD88- and TRIF-dependent pathways to promote pro-inflammatory and interferon (IFN) responses, respectively. Bacteria can inhibit the MyD88 pathway, but if the TRIF pathway is also targeted is unclear. We demonstrate that, in addition to MyD88, Yersinia pseudotuberculosis inhibits TRIF signaling through the type III secretion system effector YopJ. Suppression of TRIF signaling occurs during dendritic cell (DC) and macrophage infection and prevents expression of type I IFN and pro-inflammatory cytokines. YopJ-mediated inhibition of TRIF prevents DCs from inducing natural killer (NK) cell production of antibacterial IFNγ. During infection of DCs, YopJ potently inhibits MAPK pathways but does not prevent activation of IKK- or TBK1-dependent pathways. This singular YopJ activity efficiently inhibits TLR4 transcription-inducing activities, thus illustrating a simple means by which pathogens impede innate immunity.
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Affiliation(s)
- Charles V Rosadini
- Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Ivan Zanoni
- Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan 20126, Italy; Unit of Cell Signalling and Innate Immunity, Humanitas Clinical and Research Center, Rozzano 20089, Italy
| | - Charlotte Odendall
- Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Erin R Green
- Graduate Program in Molecular Microbiology, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Michelle K Paczosa
- Graduate Program in Immunology, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Naomi H Philip
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Igor E Brodsky
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joan Mecsas
- Graduate Program in Molecular Microbiology, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA; Graduate Program in Immunology, Sackler School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Jonathan C Kagan
- Harvard Medical School and Division of Gastroenterology, Boston Children's Hospital, Boston, MA 02115, USA.
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76
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Piscatelli HL, Li M, Zhou D. Dual 4- and 5-phosphatase activities regulate SopB-dependent phosphoinositide dynamics to promote bacterial entry. Cell Microbiol 2015; 18:705-19. [PMID: 26537021 DOI: 10.1111/cmi.12542] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 10/21/2015] [Accepted: 10/24/2015] [Indexed: 12/16/2022]
Abstract
Salmonella are able to invade non-phagocytic cells such as intestinal epithelial cells by modulating the host actin cytoskeleton to produce membrane ruffles. Two type III effector proteins SopB and SopE play key roles to this modulation. SopE is a known guanine nucleotide exchange factor (GEF) capable of activating Rac1 and CDC42. SopB is a phosphatidylinositol 4-phosphatase and 5-phosphatase promoting membrane ruffles and invasion of Salmonella through undefined mechanisms. Previous studies have demonstrated that the 4-phosphatase activity of SopB is required for PtdIns-3-phosphate (PtdIns(3)P) accumulation and SopB-mediated invasion. We show here that both the 4-phosphatase as well as the 5-phosphatase activities of SopB are essential in ruffle formation and subsequent invasion. We found that the 5-phosphatase activity of SopB is likely responsible for generating PtdIns-3,4-bisphosphate (PtdIns(3,4)P(2)) and subsequent recruitment of sorting nexin 9 (SNX9), an actin modulating protein. Intriguingly, the 4-phosphatase activity is responsible for the dephosphorylation of PtdIns(3,4)P(2) into PtdIns(3)P. Alone, neither activity is sufficient for ruffling but when acting in conjunction with one another, the 4-phosphatase and 5-phosphatase activities led to SNX9-mediated ruffling and Salmonella invasion. This work reveals the unique ability of bacterial effector protein SopB to utilize both its 4- and 5-phosphatase activities to regulate phosphoinositide dynamics to promote bacterial entry.
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Affiliation(s)
- Heather L Piscatelli
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Menghan Li
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Daoguo Zhou
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
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77
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Bugalhão JN, Mota LJ, Franco IS. Identification of regions within the Legionella pneumophila VipA effector protein involved in actin binding and polymerization and in interference with eukaryotic organelle trafficking. Microbiologyopen 2015; 5:118-33. [PMID: 26626407 PMCID: PMC4767423 DOI: 10.1002/mbo3.316] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 02/02/2023] Open
Abstract
The Legionella pneumophila effector protein VipA is an actin nucleator that co‐localizes with actin filaments and early endosomes in infected macrophages and which interferes with organelle trafficking when expressed in yeast. To identify the regions of VipA involved in its subcellular localization and functions, we ectopically expressed specific VipA mutant proteins in eukaryotic cells. This indicated that the characteristic punctate distribution of VipA depends on its NH2‐terminal (amino acid residues 1–133) and central coiled‐coil (amino acid residues 133–206) regions, and suggested a role for the COOH‐terminal (amino acid residues 206–339) region in association with actin filaments and for the NH2‐terminal in co‐localization with early endosomes. Co‐immunoprecipitation and in vitro assays showed that the COOH‐terminal region of VipA is necessary and sufficient to mediate actin binding, and is essential but insufficient to induce microfilament formation. Assays in yeast revealed that the NH2 and the COOH‐terminal regions, and possibly an NPY motif within the NH2 region of VipA, are necessary for interference with organelle trafficking. Overall, this suggests that subversion of eukaryotic vesicular trafficking by VipA involves both its ability to associate with early endosomes via its NH2‐terminal region and its capacity to bind and polymerize actin through its COOH‐terminal region.
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Affiliation(s)
- Joana N Bugalhão
- UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Departamento de Ciências da Vida, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Luís Jaime Mota
- UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Departamento de Ciências da Vida, Universidade NOVA de Lisboa, Caparica, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Irina S Franco
- UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Departamento de Ciências da Vida, Universidade NOVA de Lisboa, Caparica, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
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78
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Santos JC, Duchateau M, Fredlund J, Weiner A, Mallet A, Schmitt C, Matondo M, Hourdel V, Chamot-Rooke J, Enninga J. The COPII complex and lysosomal VAMP7 determine intracellular Salmonella localization and growth. Cell Microbiol 2015; 17:1699-720. [PMID: 26084942 DOI: 10.1111/cmi.12475] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/22/2015] [Accepted: 06/12/2015] [Indexed: 12/18/2022]
Abstract
Salmonella invades epithelial cells and survives within a membrane-bound compartment, the Salmonella-containing vacuole (SCV). We isolated and determined the host protein composition of the SCV at 30 min and 3 h of infection to identify and characterize novel regulators of intracellular bacterial localization and growth. Quantitation of the SCV protein content revealed 392 host proteins specifically enriched at SCVs, out of which 173 associated exclusively with early SCVs, 124 with maturing SCV and 95 proteins during both time-points. Vacuole interactions with endoplasmic reticulum-derived coat protein complex II vesicles modulate early steps of SCV maturation, promoting SCV rupture and bacterial hyper-replication within the host cytosol. On the other hand, SCV interactions with VAMP7-positive lysosome-like vesicles promote Salmonella-induced filament formation and bacterial growth within the late SCV. Our results reveal that the dynamic communication between the SCV and distinct host organelles affects both intracellular Salmonella localization and growth at successive steps of host cell invasion.
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Affiliation(s)
- José Carlos Santos
- Unit of Dynamics of Host-Pathogen Interactions, Institut Pasteur, Paris, France.,Graduate Program in Areas of Basic and Applied Biology (GABBA), University of Porto, Porto, Portugal
| | - Magalie Duchateau
- Structural Mass Spectrometry and Proteomics Unit, Institut Pasteur, Paris, France
| | - Jennifer Fredlund
- Unit of Dynamics of Host-Pathogen Interactions, Institut Pasteur, Paris, France
| | - Allon Weiner
- Unit of Dynamics of Host-Pathogen Interactions, Institut Pasteur, Paris, France
| | - Adeline Mallet
- Plate-forme Microscopie Ultrastructurale, Institut Pasteur, Paris, France
| | - Christine Schmitt
- Plate-forme Microscopie Ultrastructurale, Institut Pasteur, Paris, France
| | - Mariette Matondo
- Structural Mass Spectrometry and Proteomics Unit, Institut Pasteur, Paris, France
| | - Véronique Hourdel
- Structural Mass Spectrometry and Proteomics Unit, Institut Pasteur, Paris, France
| | - Julia Chamot-Rooke
- Structural Mass Spectrometry and Proteomics Unit, Institut Pasteur, Paris, France.,CNRS UMR3528, Paris, France
| | - Jost Enninga
- Unit of Dynamics of Host-Pathogen Interactions, Institut Pasteur, Paris, France
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79
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Pseudogenization of sopA and sopE2 is functionally linked and contributes to virulence of Salmonella enterica serovar Typhi. INFECTION GENETICS AND EVOLUTION 2015; 33:131-42. [DOI: 10.1016/j.meegid.2015.04.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 04/13/2015] [Accepted: 04/21/2015] [Indexed: 12/11/2022]
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80
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Scanu T, Spaapen RM, Bakker JM, Pratap CB, Wu LE, Hofland I, Broeks A, Shukla VK, Kumar M, Janssen H, Song JY, Neefjes-Borst EA, te Riele H, Holden DW, Nath G, Neefjes J. Salmonella Manipulation of Host Signaling Pathways Provokes Cellular Transformation Associated with Gallbladder Carcinoma. Cell Host Microbe 2015; 17:763-74. [PMID: 26028364 DOI: 10.1016/j.chom.2015.05.002] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/10/2015] [Accepted: 04/25/2015] [Indexed: 12/11/2022]
Abstract
Cancer is fueled by deregulation of signaling pathways in control of cellular growth and proliferation. These pathways are also targeted by infectious pathogens en route to establishing infection. Gallbladder carcinoma (GBC) is frequent in the Indian subcontinent, with chronic Salmonella enterica serovar Typhi infection reported as a significant risk factor. However, direct association and causal mechanisms between Salmonella Typhi infection and GBC have not been established. Deconstructing the epidemiological association between GBC and Salmonella Typhi infection, we show that Salmonella enterica induces malignant transformation in predisposed mice, murine gallbladder organoids, and fibroblasts, with TP53 mutations and c-MYC amplification. Mechanistically, activation of MAPK and AKT pathways, mediated by Salmonella enterica effectors secreted during infection, is critical to both ignite and sustain transformation, consistent with observations in GBC patients from India. Collectively, our findings indicate that Salmonella enterica can promote transformation of genetically predisposed cells and is a causative agent of GBC.
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Affiliation(s)
- Tiziana Scanu
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands.
| | - Robbert M Spaapen
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Jeroen M Bakker
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Chandra Bhan Pratap
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
| | - Lin-en Wu
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Ingrid Hofland
- Core Facility Molecular Pathology and Biobanking, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Annegien Broeks
- Core Facility Molecular Pathology and Biobanking, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Vijay Kumar Shukla
- Department of General Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
| | - Mohan Kumar
- Department of Pathology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
| | - Hans Janssen
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Ji-Ying Song
- Division of Experimental Animal Pathology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - E Andra Neefjes-Borst
- Department of Pathology, Free University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, the Netherlands
| | - Hein te Riele
- Division of Biological Stress Response, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - David W Holden
- Center for Molecular Bacteriology and Infection, Imperial College London, London SW72AZ, UK
| | - Gopal Nath
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
| | - Jacques Neefjes
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands.
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81
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The impact of phosphorus on the immune system and the intestinal microbiota with special focus on the pig. Nutr Res Rev 2015; 28:67-82. [PMID: 26004147 DOI: 10.1017/s0954422415000049] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
There is increasing interest in dietary ingredients that are appropriate to support digestive and immune functions, but also maintain a stable microbial ecosystem in the gastrointestinal tract (GIT), particularly in weaned pigs. P is an essential nutrient for both microbes and their host, as it is involved, for example, in bone formation, energy metabolism, cellular signalling and stabilisation of cell membranes. Non-ruminant animals have limited access to phytate, the main storage form of P in plant seeds. The release of P bound to phytate requires phytase activity of plant or microbial origin, resulting in the formation of variable phosphorylated inositol phosphates (InsPs). The present review focuses on interactions between variations in dietary P supply, the immune system of the host, and the intestinal microbial ecosystem. Although results on the interaction between P and the immune system are inconsistent, several studies in different species have shown a positive impact of dietary P and phytase addition on the adaptive immune response. Recent studies with pigs suggest that P supply may influence intestinal microbial composition and activity. Individual InsPs or phosphate may also affect properties of pathogenic micro-organisms, such as metabolism or virulence. In conclusion, P may be considered as part of an integrated approach to support immune functions and maintain a stable microbial ecosystem in the GIT, thereby providing a barrier against potential pathogens. Within this regard, differences in phytate-P content and intrinsic phytase activity of plant feedstuffs, as well as the formation of individual InsPs, have to be taken into account.
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82
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Zheng K, Kitazato K, Wang Y, He Z. Pathogenic microbes manipulate cofilin activity to subvert actin cytoskeleton. Crit Rev Microbiol 2015; 42:677-95. [PMID: 25853495 DOI: 10.3109/1040841x.2015.1010139] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Actin-depolymerizing factor (ADF)/cofilin proteins are key players in controlling the temporal and spatial extent of actin dynamics, which is crucial for mediating host-pathogen interactions. Pathogenic microbes have evolved molecular mechanisms to manipulate cofilin activity to subvert the actin cytoskeletal system in host cells, promoting their internalization into the target cells, modifying the replication niche and facilitating their intracellular and intercellular dissemination. The study of how these pathogens exploit cofilin pathways is crucial for understanding infectious disease and providing potential targets for drug therapies.
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Affiliation(s)
- Kai Zheng
- a Department of Pharmacy, School of Medicine , Shenzhen University , Shenzhen , Guangdong , People's Republic of China .,c Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University , Guangzhou , China
| | - Kaio Kitazato
- b Division of Molecular Pharmacology of Infectious Agents, Department of Molecular Microbiology and Immunology , Nagasaki University , Nagasaki , Japan , and
| | - Yifei Wang
- c Guangzhou Jinan Biomedicine Research and Development Center, National Engineering Research Center of Genetic Medicine, Jinan University , Guangzhou , China
| | - Zhendan He
- a Department of Pharmacy, School of Medicine , Shenzhen University , Shenzhen , Guangdong , People's Republic of China
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83
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Abstract
Salmonellae invasion and intracellular replication within host cells result in a range of diseases, including gastroenteritis, bacteraemia, enteric fever and focal infections. In recent years, considerable progress has been made in our understanding of the molecular mechanisms that salmonellae use to alter host cell physiology; through the delivery of effector proteins with specific activities and through the modulation of defence and stress response pathways. In this Review, we summarize our current knowledge of the complex interplay between bacterial and host factors that leads to inflammation, disease and, in most cases, control of the infection by its animal hosts, with a particular focus on Salmonella enterica subsp. enterica serovar Typhimurium. We also highlight gaps in our knowledge of the contributions of salmonellae and the host to disease pathogenesis, and we suggest future avenues for further study.
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Affiliation(s)
- Doris L. LaRock
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Anu Chaudhary
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Samuel I. Miller
- Department of Microbiology, University of Washington, Seattle, WA 98195
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
- Department of Immunology, University of Washington, Seattle, WA 98195
- Department of Medicine, University of Washington, Seattle, WA 98195
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84
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de Souza Santos M, Orth K. Subversion of the cytoskeleton by intracellular bacteria: lessons from Listeria, Salmonella and Vibrio. Cell Microbiol 2015; 17:164-73. [PMID: 25440316 PMCID: PMC5806695 DOI: 10.1111/cmi.12399] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 10/29/2014] [Accepted: 11/07/2014] [Indexed: 12/18/2022]
Abstract
Entry into host cells and intracellular persistence by invasive bacteria are tightly coupled to the ability of the bacterium to disrupt the eukaryotic cytoskeletal machinery. Herein we review the main strategies used by three intracellular pathogens to harness key modulators of the cytoskeleton. Two of these bacteria, namely Listeria monocytogenes and Salmonella enterica serovar Typhimurium, exhibit quite distinct intracellular lifestyles and therefore provide a comprehensive panel for the understanding of the intricate bacteria-cytoskeleton interplay during infections. The emerging intracellular pathogen Vibrio parahaemolyticus is depicted as a developing model for the uncovering of novel mechanisms used to hijack the cytoskeleton.
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Affiliation(s)
- Marcela de Souza Santos
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kim Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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85
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Lhocine N, Arena ET, Bomme P, Ubelmann F, Prévost MC, Robine S, Sansonetti PJ. Apical invasion of intestinal epithelial cells by Salmonella typhimurium requires villin to remodel the brush border actin cytoskeleton. Cell Host Microbe 2015; 17:164-77. [PMID: 25600187 PMCID: PMC4346658 DOI: 10.1016/j.chom.2014.12.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 09/16/2014] [Accepted: 12/04/2014] [Indexed: 01/16/2023]
Abstract
Salmonella invasion of intestinal epithelial cells requires extensive, though transient, actin modifications at the site of bacterial entry. The actin-modifying protein villin is present in the brush border where it participates in the constitution of microvilli and in epithelial restitution after damage through its actin-severing activity. We investigated a possible role for villin in Salmonella invasion. The absence of villin, which is normally located at the bacterial entry site, leads to a decrease in Salmonella invasion. Villin is necessary for early membrane-associated processes and for optimal ruffle assembly by balancing the steady-state level of actin. The severing activity of villin is important for Salmonella invasion in vivo. The bacterial phosphatase SptP tightly regulates villin phosphorylation, while the actin-binding effector SipA protects F-actin and counterbalances villin-severing activity. Thus, villin plays an important role in establishing the balance between actin polymerization and actin severing to facilitate the initial steps of Salmonella entry. The host actin-binding protein villin is required for Salmonella apical invasion Villin plays a role in Salmonella ruffle formation and actin dynamics Villin-severing activity promotes Salmonella invasion in cells and in vivo The bacterial effectors SipA and SptP regulate villin activities
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Affiliation(s)
- Nouara Lhocine
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France; INSERM U786, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
| | - Ellen T Arena
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France; INSERM U786, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
| | - Perrine Bomme
- Plateforme de Microscopie Ultrastructurale, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
| | - Florent Ubelmann
- Unité Mixte de Recherche 144, Institut Curie, 75248 Paris Cedex 05, France; Centro de Estudos de Doenças Crónicas (CEDOC), Faculdade de Ciencias Médicas, Universidade Nova de Lisboa, 1169-056, Portugal
| | - Marie-Christine Prévost
- Plateforme de Microscopie Ultrastructurale, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
| | - Sylvie Robine
- Unité Mixte de Recherche 144, Institut Curie, 75248 Paris Cedex 05, France
| | - Philippe J Sansonetti
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France; INSERM U786, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France; Collège de France, 11 Place Marcelin Berthelot, 75005 Paris, France.
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86
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Hänisch J, Stradal TE, Rottner K. A novel contractility pathway operating in Salmonella invasion. Virulence 2014; 3:81-6. [DOI: 10.4161/viru.3.1.18454] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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87
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Franco IS, Shuman HA. A pathogen's journey in the host cell: Bridges between actin and traffic. BIOARCHITECTURE 2014; 2:38-42. [PMID: 22754628 PMCID: PMC3383720 DOI: 10.4161/bioa.20422] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Manipulation of the actin cytoskeleton is a commonly used process by which bacterial pathogens and viruses are able to neutralize host defense mechanisms and subvert them in order to replicate in a hostile environment. Diverse bacteria display a wide array of mechanisms of regulation of microfilaments to enter, move within or exit the host cell. A less studied subject is how pathogens may co-opt the actin cytoskeleton to disturb vesicle trafficking pathways, namely phagolysosomal fusion, and avoid degradation. In fact, although actin plays a role in endosomal trafficking and phagosome maturation, the knowledge on the exact mechanisms and additional players is still scarce. Recently, we found that the Legionella pneumophila virulence factor VipA is an actin nucleator, associates with actin filaments and early endosomes during infection, and interferes in yeast organelle trafficking pathways, suggesting it may be linking actin dynamics to endosome biogenesis. Further studies on this protein, together with work on other bacterial effectors, may help shed light in the role of actin in endosomal maturation.
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88
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Asrat S, de Jesús DA, Hempstead AD, Ramabhadran V, Isberg RR. Bacterial Pathogen Manipulation of Host Membrane Trafficking. Annu Rev Cell Dev Biol 2014; 30:79-109. [DOI: 10.1146/annurev-cellbio-100913-013439] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Seblewongel Asrat
- Howard Hughes Medical Institute,
- Department of Molecular Biology and Microbiology, and
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, Massachusetts, 02111; , , , ,
| | - Dennise A. de Jesús
- Department of Molecular Biology and Microbiology, and
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, Massachusetts, 02111; , , , ,
| | - Andrew D. Hempstead
- Department of Molecular Biology and Microbiology, and
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Science, Tufts University School of Medicine, Boston, Massachusetts, 02111; , , , ,
| | - Vinay Ramabhadran
- Howard Hughes Medical Institute,
- Department of Molecular Biology and Microbiology, and
| | - Ralph R. Isberg
- Howard Hughes Medical Institute,
- Department of Molecular Biology and Microbiology, and
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89
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Pizarro-Cerdá J, Kühbacher A, Cossart P. Phosphoinositides and host-pathogen interactions. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:911-8. [PMID: 25241942 DOI: 10.1016/j.bbalip.2014.09.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 01/08/2023]
Abstract
Phosphoinositides control key cellular processes including vesicular trafficking and actin polymerization. Intracellular bacterial pathogens manipulate phosphoinositide metabolism in order to promote their uptake by target cells and to direct in some cases the biogenesis of their replication compartments. In this chapter, we review the molecular strategies that major pathogens including Listeria, Mycobacterium, Shigella, Salmonella, Legionella and Yersinia use to hijack phosphoinositides during infection. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- Javier Pizarro-Cerdá
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France; INSERM, U604, F-75015 Paris, France; INRA, USC2020, F-75015 Paris, France
| | - Andreas Kühbacher
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Department of Molecular Biotechnology, Stuttgart G-70569, Germany
| | - Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France; INSERM, U604, F-75015 Paris, France; INRA, USC2020, F-75015 Paris, France
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90
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Vonaesch P, Sellin ME, Cardini S, Singh V, Barthel M, Hardt WD. The Salmonella Typhimurium effector protein SopE transiently localizes to the early SCV and contributes to intracellular replication. Cell Microbiol 2014; 16:1723-35. [PMID: 25052734 DOI: 10.1111/cmi.12333] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 06/19/2014] [Accepted: 07/05/2014] [Indexed: 12/28/2022]
Abstract
Salmonella enterica serovar Typhimurium (S. Tm) is a facultative intracellular pathogen that induces entry into non-phagocytic cells by a Type III secretion system (TTSS) and cognate effector proteins. Upon host cell entry, S. Tm expresses a second TTSS and subverts intracellular trafficking to create a replicative niche - the Salmonella-containing vacuole (SCV). SopE, a guanidyl exchange factor (GEF) for Rac1 and Cdc42, is translocated by the TTSS-1 upon host cell contact and promotes entry through triggering of actin-dependent ruffles. After host cell entry, the bulk of SopE undergoes proteasomal degradation. Here we show that a subfraction is however detectable on the nascent SCV membrane up to ∼ 6 h post infection. Membrane localization of SopE and the closely related SopE2 differentially depend on the Rho-GTPase-binding GEF domain, and to some extent involves also the unstructured N-terminus. SopE localizes transiently to the early SCV, dependent on continuous synthesis and secretion by the TTSS-1 during the intracellular state. Mutant strains lacking SopE or SopE2 are attenuated in early intracellular replication, while complementation restores this defect. Hence, the present study reveals an unanticipated role for SopE and SopE2 in establishing the Salmonella replicative niche, and further emphasizes the importance of entry effectors in later stages of host-cell manipulation.
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Affiliation(s)
- Pascale Vonaesch
- Institute of Microbiology, ETH Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland
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91
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Salmonella enterica Serovar Typhi conceals the invasion-associated type three secretion system from the innate immune system by gene regulation. PLoS Pathog 2014; 10:e1004207. [PMID: 24992093 PMCID: PMC4081808 DOI: 10.1371/journal.ppat.1004207] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 05/10/2014] [Indexed: 01/13/2023] Open
Abstract
Delivery of microbial products into the mammalian cell cytosol by bacterial secretion systems is a strong stimulus for triggering pro-inflammatory host responses. Here we show that Salmonella enterica serovar Typhi (S. Typhi), the causative agent of typhoid fever, tightly regulates expression of the invasion-associated type III secretion system (T3SS-1) and thus fails to activate these innate immune signaling pathways. The S. Typhi regulatory protein TviA rapidly repressed T3SS-1 expression, thereby preventing RAC1-dependent, RIP2-dependent activation of NF-κB in epithelial cells. Heterologous expression of TviA in S. enterica serovar Typhimurium (S. Typhimurium) suppressed T3SS-1-dependent inflammatory responses generated early after infection in animal models of gastroenteritis. These results suggest that S. Typhi reduces intestinal inflammation by limiting the induction of pathogen-induced processes through regulation of virulence gene expression. Bacterial pathogens translocate effector proteins into the cytoplasm of host cells to manipulate the mammalian host. These processes, e.g. the stimulation of small regulatory GTPases, activate the innate immune system and induce pro-inflammatory responses aimed at clearing invading microbes from the infected tissue. Here we show that strict regulation of virulence gene expression can be used as a strategy to limit the induction of inflammatory responses while retaining the ability to manipulate the host. Upon entry into host tissue, Salmonella enterica serovar Typhi, the causative agent of typhoid fever, rapidly represses expression of a virulence factor required for entering tissue to avoid detection by the host innate immune surveillance. This tight control of virulence gene expression enables the pathogen to deploy a virulence factor for epithelial invasion, while preventing the subsequent generation of pro-inflammatory responses in host cells. We conclude that regulation of virulence gene expression contributes to innate immune evasion during typhoid fever by concealing a pattern of pathogenesis.
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92
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Truong D, Copeland JW, Brumell JH. Bacterial subversion of host cytoskeletal machinery: hijacking formins and the Arp2/3 complex. Bioessays 2014; 36:687-96. [PMID: 24849003 DOI: 10.1002/bies.201400038] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The host actin nucleation machinery is subverted by many bacterial pathogens to facilitate their entry, motility, replication, and survival. The majority of research conducted in the past primarily focused on exploitation of a host actin nucleator, the Arp2/3 complex, by bacterial pathogens. Recently, new studies have begun to explore the role of formins, another family of host actin nucleators, in bacterial pathogenesis. This review provides an overview of recent advances in the study of the exploitation of the Arp2/3 complex and formins by bacterial pathogens. Secreted bacterial effector proteins seem to manipulate the regulation of these actin nucleators or functionally mimic them to drive bacterial entry, motility and survival within host cells. An enhanced understanding of how formins are exploited will provide us with greater insight into how a fundamental eurkaryotic cellular process is utilized by bacteria and will also advance our knowledge of host-pathogen interactions.
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Affiliation(s)
- Dorothy Truong
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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93
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Popoff MR. Bacterial factors exploit eukaryotic Rho GTPase signaling cascades to promote invasion and proliferation within their host. Small GTPases 2014; 5:28209. [PMID: 25203748 DOI: 10.4161/sgtp.28209] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Actin cytoskeleton is a main target of many bacterial pathogens. Among the multiple regulation steps of the actin cytoskeleton, bacterial factors interact preferentially with RhoGTPases. Pathogens secrete either toxins which diffuse in the surrounding environment, or directly inject virulence factors into target cells. Bacterial toxins, which interfere with RhoGTPases, and to some extent with RasGTPases, catalyze a covalent modification (ADPribosylation, glucosylation, deamidation, adenylation, proteolysis) blocking these molecules in their active or inactive state, resulting in alteration of epithelial and/or endothelial barriers, which contributes to dissemination of bacteria in the host. Injected bacterial virulence factors preferentially manipulate the RhoGTPase signaling cascade by mimicry of eukaryotic regulatory proteins leading to local actin cytoskeleton rearrangement, which mediates bacterial entry into host cells or in contrast escape to phagocytosis and immune defense. Invasive bacteria can also manipulate RhoGTPase signaling through recognition and stimulation of cell surface receptor(s). Changes in RhoGTPase activation state is sensed by the innate immunity pathways and allows the host cell to adapt an appropriate defense response.
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Affiliation(s)
- Michel R Popoff
- Unité des Bactéries anaérobies et Toxines; Institut Pasteur; Paris, France
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94
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Ruan HH, Li Y, Zhang XX, Liu Q, Ren H, Zhang KS, Zhao H. Identification of TRAF6 as a ubiquitin ligase engaged in the ubiquitination of SopB, a virulence effector protein secreted by Salmonella typhimurium. Biochem Biophys Res Commun 2014; 447:172-7. [PMID: 24704445 DOI: 10.1016/j.bbrc.2014.03.126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 03/25/2014] [Indexed: 10/25/2022]
Abstract
The phosphoinositide phosphatase SopB is one of the effectors injected by Salmonella typhimurium (S.typhimurium) that diversifies its function through a ubiquitin-dependent differential localization. However, it is unclear which E3 ubiquitin ligase is responsible for ubiquitination of SopB. Based on the E1-E2-E3 trio of enzymes responsible for the ubiquitin activation and translocation to substrate proteins, we constructed an in vitro assay of SopB ubiquitination. Using this assay, we purified an E3 ubiquitin ligase, TRAF6, from the Henle-407 S100 extraction that may be responsible for the ubiquitination of SopB. To investigate the functional correlation of TRAF6, we showed that recombinant TRAF6 specifically ubiquitinates SopB in a dose-dependent manner in vitro. Upon infection, the ubiquitination of SopB was absolutely blocked by TRAF6 deletion, as shown in Traf6(-/-) mouse embryonic fibroblasts (MEFs) compared with Traf6(+/+) MEFs. However, the ectopic expression of TRAF6 in Traf6(-/-) MEFs rescued the two species of ubiquitin-conjugated SopB, which strengthens the role of TRAF6 in SopB ubiquitination. The analysis of E2 revealed that UbcH5c and not other E2 conjugating enzymes are required for TRAF6-mediated SopB ubiquitination both in vitro and in vivo. In summary, these results suggest the relevance of UbcH5c/TRAF6 in SopB during S.typhimurium infection and thereby imply that S.typhimurium has evolved a mechanism of utilizing the host's E3 ubiquitin ligase to modify and modulate the function of its effector protein in order to ensure pathogen and host cell survival.
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Affiliation(s)
- Hai-Hua Ruan
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China.
| | - Ye Li
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China
| | - Xi-Xuan Zhang
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China
| | - Qiang Liu
- Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, China
| | - He Ren
- Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University Cancer Hospital, Tianjin 300071, China
| | - Kun-Sheng Zhang
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China
| | - Hui Zhao
- Tianjin Key Laboratory of Food Science and Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China.
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95
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Wynosky-Dolfi MA, Snyder AG, Philip NH, Doonan PJ, Poffenberger MC, Avizonis D, Zwack EE, Riblett AM, Hu B, Strowig T, Flavell RA, Jones RG, Freedman BD, Brodsky IE. Oxidative metabolism enables Salmonella evasion of the NLRP3 inflammasome. ACTA ACUST UNITED AC 2014; 211:653-68. [PMID: 24638169 PMCID: PMC3978275 DOI: 10.1084/jem.20130627] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Salmonella lacking the TCA enzyme aconitase trigger NLRP3 inflammasome activation in infected macrophages, leading to elevated inflammatory responses and reduced virulence. Microbial infection triggers assembly of inflammasome complexes that promote caspase-1–dependent antimicrobial responses. Inflammasome assembly is mediated by members of the nucleotide binding domain leucine-rich repeat (NLR) protein family that respond to cytosolic bacterial products or disruption of cellular processes. Flagellin injected into host cells by invading Salmonella induces inflammasome activation through NLRC4, whereas NLRP3 is required for inflammasome activation in response to multiple stimuli, including microbial infection, tissue damage, and metabolic dysregulation, through mechanisms that remain poorly understood. During systemic infection, Salmonella avoids NLRC4 inflammasome activation by down-regulating flagellin expression. Macrophages exhibit delayed NLRP3 inflammasome activation after Salmonella infection, suggesting that Salmonella may evade or prevent the rapid activation of the NLRP3 inflammasome. We therefore screened a Salmonella Typhimurium transposon library to identify bacterial factors that limit NLRP3 inflammasome activation. Surprisingly, absence of the Salmonella TCA enzyme aconitase induced rapid NLRP3 inflammasome activation. This inflammasome activation correlated with elevated levels of bacterial citrate, and required mitochondrial reactive oxygen species and bacterial citrate synthase. Importantly, Salmonella lacking aconitase displayed NLRP3- and caspase-1/11–dependent attenuation of virulence, and induced elevated serum IL-18 in wild-type mice. Together, our data link Salmonella genes controlling oxidative metabolism to inflammasome activation and suggest that NLRP3 inflammasome evasion promotes systemic Salmonella virulence.
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Affiliation(s)
- Meghan A Wynosky-Dolfi
- Department of Pathobiology, School of Veterinary Medicine; and 2 Immunology Graduate Group and 3 Cell and Molecular Biology Graduate Group, University of Pennsylvania, Kennett Square, PA 19104
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96
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Lim JS, Shin M, Kim HJ, Kim KS, Choy HE, Cho KA. Caveolin-1 mediates Salmonella invasion via the regulation of SopE-dependent Rac1 activation and actin reorganization. J Infect Dis 2014; 210:793-802. [PMID: 24625804 DOI: 10.1093/infdis/jiu152] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Caveolar endocytosis has an important function in the cellular uptake of some bacterial toxins, viruses, and circulating proteins. However, the molecular machinery involved in caveolae-dependent bacterial endocytosis is poorly defined. In the present study, we identify a new molecular mechanism for the caveolin-1-dependent entry of Salmonella into host cells via the direct regulation of actin reorganization. In contrast to the interaction of caveolae with other pathogens, the caveolae did not form Salmonella-containing vesicles or endosomes in the host cells. Instead, the caveolae rapidly moved to the apical plasma membrane upon actin condensation during early invasion. Interestingly, the injected bacterial protein SopE interacted with Rac1 to regulate actin reorganization, and both proteins colocalized and directly interacted with caveolin-1 in caveolae during early invasion. After the complete internalization of Salmonella, SopE levels decreased both in the caveolae and in the host cytoplasm; Rac1 activity was also decreased. Downregulation of caveolin-1 by siRNA treatment led to reduction of Salmonella invasion compared with control siRNA-treated cells. These results suggest a new model in which caveolin-1 might be involved in Salmonella entry via its interaction with SopE and Rac1, leading to enhanced membrane ruffling for phagocytosis into host cells.
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Affiliation(s)
| | | | | | - Kyu Suk Kim
- Department of Biochemistry Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju, Korea
| | | | - Kyung A Cho
- Department of Biochemistry Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju, Korea
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97
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Abstract
Autophagy is a process whereby a double-membrane structure (autophagosome) engulfs unnecessary cytosolic proteins, organelles, and invading pathogens and delivers them to the lysosome for degradation. We examined the fate of cytosolic Salmonella targeted by autophagy and found that autophagy-targeted Salmonella present in the cytosol of HeLa cells correlates with intracellular bacterial replication. Real-time analyses revealed that a subset of cytosolic Salmonella extensively associates with autophagy components p62 and/or LC3 and replicates quickly, whereas intravacuolar Salmonella shows no or very limited association with p62 or LC3 and replicates much more slowly. Replication of cytosolic Salmonella in HeLa cells is significantly decreased when autophagy components are depleted. Eventually, hyperreplication of cytosolic Salmonella potentiates cell detachment, facilitating the dissemination of Salmonella to neighboring cells. We propose that Salmonella benefits from autophagy for its cytosolic replication in HeLa cells. As a host defense system, autophagy is known to target a population of Salmonella for degradation and hence restricting Salmonella replication. In contrast to this concept, a recent report showed that knockdown of Rab1, a GTPase required for autophagy of Salmonella, decreases Salmonella replication in HeLa cells. Here, we have reexamined the fate of Salmonella targeted by autophagy by various cell biology-based assays. We found that the association of autophagy components with cytosolic Salmonella increases shortly after initiation of intracellular bacterial replication. Furthermore, through a live-cell imaging method, a subset of cytosolic Salmonella was found to be extensively associated with autophagy components p62 and/or LC3, and they replicated quickly. Most importantly, depletion of autophagy components significantly reduced the replication of cytosolic Salmonella in HeLa cells. Hence, in contrast to previous reports, we propose that autophagy facilitates Salmonella replication in the cytosol of HeLa cells.
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98
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Puhar A, Tronchère H, Payrastre B, Nhieu GTV, Sansonetti PJ. A Shigella effector dampens inflammation by regulating epithelial release of danger signal ATP through production of the lipid mediator PtdIns5P. Immunity 2014; 39:1121-31. [PMID: 24332032 DOI: 10.1016/j.immuni.2013.11.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 10/09/2013] [Indexed: 12/20/2022]
Abstract
Upon infection with Shigella flexneri, epithelial cells release ATP through connexin hemichannels. However, the pathophysiological consequence and the regulation of this process are unclear. Here we showed that in intestinal epithelial cell ATP release was an early alert response to infection with enteric pathogens that eventually promoted inflammation of the gut. Shigella evolved to escape this inflammatory reaction by its type III secretion effector IpgD, which blocked hemichannels via the production of the lipid PtdIns5P. Infection with an ipgD mutant resulted in rapid hemichannel-dependent accumulation of extracellular ATP in vitro and in vivo, which preceded the onset of inflammation. At later stages of infection, ipgD-deficient Shigella caused strong intestinal inflammation owing to extracellular ATP. We therefore describe a new paradigm of host-pathogen interaction based on endogenous danger signaling and identify extracellular ATP as key regulator of mucosal inflammation during infection. Our data provide new angles of attack for the development of anti-inflammatory molecules.
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Affiliation(s)
- Andrea Puhar
- Inserm U786, Unité de Pathogénie Microbienne Moléculaire, 75724 Paris Cedex 15, France; Institut Pasteur, Unité de Pathogénie Microbienne Moléculaire, 75724 Paris Cedex 15, France.
| | - Hélène Tronchère
- Inserm U1048, I2MC, 31432 Toulouse Cedex 4, France; Université Toulouse 3, I2MC, 31432 Toulouse Cedex 4, France
| | - Bernard Payrastre
- Inserm U1048, I2MC, 31432 Toulouse Cedex 4, France; Université Toulouse 3, I2MC, 31432 Toulouse Cedex 4, France; CHU Toulouse, Laboratoire d'Hématologie, 31432 Toulouse Cedex 4, France
| | - Guy Tran Van Nhieu
- Inserm U1050, Equipe Communication Intercellulaire et Infections Microbiennes, CIRB, 75231 Paris Cedex 5, France; CNRS UMR7241, Equipe Communication Intercellulaire et Infections Microbiennes, CIRB, 75231 Paris Cedex 5, France; Collège de France, Equipe Communication Intercellulaire et Infections Microbiennes, CIRB, 75231 Paris Cedex 5, France
| | - Philippe J Sansonetti
- Inserm U786, Unité de Pathogénie Microbienne Moléculaire, 75724 Paris Cedex 15, France; Institut Pasteur, Unité de Pathogénie Microbienne Moléculaire, 75724 Paris Cedex 15, France.
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99
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Jolly C, Winfree S, Hansen B, Steele-Mortimer O. The Annexin A2/p11 complex is required for efficient invasion of Salmonella Typhimurium in epithelial cells. Cell Microbiol 2014; 16:64-77. [PMID: 23931152 PMCID: PMC3921270 DOI: 10.1111/cmi.12180] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 08/01/2013] [Accepted: 08/02/2013] [Indexed: 12/21/2022]
Abstract
The facultative intracellular pathogen, Salmonella enterica, triggers its own uptake into non-phagocytic epithelial cells. Invasion is dependent on a type 3 secretion system (T3SS), which delivers a cohort of effector proteins across the plasma membrane where they induce dynamic actin-driven ruffling of the membrane and ultimately, internalization of the bacteria into a modified phagosome. In eukaryotic cells, the calcium- and phospholipid-binding protein Annexin A2 (AnxA2) functions as a platform for actin remodelling in the vicinity of dynamic cellular membranes. AnxA2 is mostly found in a stable heterotetramer, with p11, which can interact with other proteins such as the giant phosphoprotein AHNAK. We show here that AnxA2, p11 and AHNAK are required for T3SS-mediated Salmonella invasion of cultured epithelial cells and that the T3SS effector SopB is required for recruitment of AnxA2 and AHNAK to Salmonella invasion sites. Altogether this work shows that, in addition to targeting Rho-family GTPases, Salmonella can intersect the host cell actin pathway via AnxA2.
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Affiliation(s)
- Carrie Jolly
- Salmonella Host-Cell Interactions Section, Laboratory of Intracellular Parasites, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, Montana, 59840, USA
| | - Seth Winfree
- Salmonella Host-Cell Interactions Section, Laboratory of Intracellular Parasites, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, Montana, 59840, USA
| | - Bryan Hansen
- Microscopy Unit, Research Technology Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, Montana, 59840, USA
| | - Olivia Steele-Mortimer
- Salmonella Host-Cell Interactions Section, Laboratory of Intracellular Parasites, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, Montana, 59840, USA
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100
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Keestra AM, Bäumler AJ. Detection of enteric pathogens by the nodosome. Trends Immunol 2013; 35:123-30. [PMID: 24268520 DOI: 10.1016/j.it.2013.10.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 10/23/2013] [Accepted: 10/24/2013] [Indexed: 01/31/2023]
Abstract
Nucleotide-binding oligomerization domain protein (NOD)1 and NOD2 participate in signaling pathways that detect pathogen-induced processes, such as the presence of peptidoglycan fragments in the host cell cytosol, as danger signals. Recent work suggests that peptidoglycan fragments activate NOD1 indirectly, through activation of the small Rho GTPase Ras-related C3 botulinum toxin substrate 1 (RAC1). Excessive activation of small Rho GTPases by virulence factors of enteric pathogens also triggers the NOD1 signaling pathway. Many enteric pathogens use virulence factors that alter the activation state of small Rho GTPases, thereby manipulating the host cell cytoskeleton of intestinal epithelial cells to promote bacterial attachment or entry. These data suggest that the NOD1 signaling pathway in intestinal epithelial cells provides an important sentinel function for detecting 'breaking and entering' by enteric pathogens.
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Affiliation(s)
- A Marijke Keestra
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, One Shields Avenue, Davis CA 95616, USA
| | - Andreas J Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, One Shields Avenue, Davis CA 95616, USA.
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