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Chatterjee R, Setty SRG, Chakravortty D. SNAREs: a double-edged sword for intravacuolar bacterial pathogens within host cells. Trends Microbiol 2024; 32:477-493. [PMID: 38040624 DOI: 10.1016/j.tim.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 12/03/2023]
Abstract
In the tug-of-war between host and pathogen, both evolve to combat each other's defence arsenals. Intracellular phagosomal bacteria have developed strategies to modify the vacuolar niche to suit their requirements best. Conversely, the host tries to target the pathogen-containing vacuoles towards the degradative pathways. The host cells use a robust system through intracellular trafficking to maintain homeostasis inside the cellular milieu. In parallel, intracellular bacterial pathogens have coevolved with the host to harbour strategies to manipulate cellular pathways, organelles, and cargoes, facilitating the conversion of the phagosome into a modified pathogen-containing vacuole (PCV). Key molecular regulators of intracellular traffic, such as changes in the organelle (phospholipid) composition, recruitment of small GTPases and associated effectors, soluble N-ethylmaleimide-sensitive factor-activating protein receptors (SNAREs), etc., are hijacked to evade lysosomal degradation. Legionella, Salmonella, Coxiella, Chlamydia, Mycobacterium, and Brucella are examples of pathogens which diverge from the endocytic pathway by using effector-mediated mechanisms to overcome the challenges and establish their intracellular niches. These pathogens extensively utilise and modulate the end processes of secretory pathways, particularly SNAREs, in repurposing the PCV into specialised compartments resembling the host organelles within the secretory network; at the same time, they avoid being degraded by the host's cellular mechanisms. Here, we discuss the recent research advances on the host-pathogen interaction/crosstalk that involves host SNAREs, conserved cellular processes, and the ongoing host-pathogen defence mechanisms in the molecular arms race against each other. The current knowledge of SNAREs, and intravacuolar bacterial pathogen interactions, enables us to understand host cellular innate immune pathways, maintenance of homeostasis, and potential therapeutic strategies to combat ever-growing antimicrobial resistance.
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Affiliation(s)
- Ritika Chatterjee
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India
| | - Subba Rao Gangi Setty
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India.
| | - Dipshikha Chakravortty
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka, India; Adjunct Faculty, Indian Institute of Science Research and Education, Thiruvananthapuram, Kerala, India.
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2
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Meier K, Jachmann LH, Türköz G, Babu Sait MR, Pérez L, Kepp O, Valdivia RH, Kroemer G, Sixt BS. The Chlamydia effector CpoS modulates the inclusion microenvironment and restricts the interferon response by acting on Rab35. mBio 2023; 14:e0319022. [PMID: 37530528 PMCID: PMC10470785 DOI: 10.1128/mbio.03190-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 06/13/2023] [Indexed: 08/03/2023] Open
Abstract
The obligate intracellular bacterium Chlamydia trachomatis inserts a family of inclusion membrane (Inc) proteins into the membrane of its vacuole (the inclusion). The Inc CpoS is a critical suppressor of host cellular immune surveillance, but the underlying mechanism remained elusive. By complementing a cpoS mutant with various natural orthologs and variants of CpoS, we linked distinct molecular interactions of CpoS to distinct functions. Unexpectedly, we found CpoS to be essential for the formation of inclusion membrane microdomains that control the spatial organization of multiple Incs involved in signaling and modulation of the host cellular cytoskeleton. While the function of CpoS in microdomains was uncoupled from its role in the suppression of host cellular defenses, we found the ability of CpoS to interact with Rab GTPases to be required not only for the manipulation of membrane trafficking, such as to mediate transport of ceramide-derived lipids (sphingolipids) to the inclusion, but also for the inhibition of Stimulator of interferon genes (STING)-dependent type I interferon responses. Indeed, depletion of Rab35 phenocopied the exacerbated interferon responses observed during infection with CpoS-deficient mutants. Overall, our findings highlight the role of Inc-Inc interactions in shaping the inclusion microenvironment and the modulation of membrane trafficking as a pathogenic immune evasion strategy. IMPORTANCE Chlamydia trachomatis is a prevalent bacterial pathogen that causes blinding ocular scarring and urogenital infections that can lead to infertility and pregnancy complications. Because Chlamydia can only grow within its host cell, boosting the intrinsic defenses of human cells may represent a novel strategy to fight pathogen replication and survival. Hence, CpoS, a Chlamydia protein known to block host cellular defenses, or processes regulated by CpoS, could provide new opportunities for therapeutic intervention. By revealing CpoS as a multifunctional virulence factor and by linking its ability to block host cellular immune signaling to the modulation of membrane trafficking, the present work may provide a foundation for such rationale targeting and advances our understanding of how intracellular bacteria can shape and protect their growth niche.
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Affiliation(s)
- Karsten Meier
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Lana H. Jachmann
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Gözde Türköz
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Mohammed Rizwan Babu Sait
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Lucía Pérez
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Oliver Kepp
- Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France
| | - Raphael H. Valdivia
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Guido Kroemer
- Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France
- Department of Biology, Institut du Cancer Paris CARPEM, Hôpital Européen Georges-Pompidou, AP-HP, Paris, France
| | - Barbara S. Sixt
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
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3
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Clemente TM, Angara RK, Gilk SD. Establishing the intracellular niche of obligate intracellular vacuolar pathogens. Front Cell Infect Microbiol 2023; 13:1206037. [PMID: 37645379 PMCID: PMC10461009 DOI: 10.3389/fcimb.2023.1206037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
Obligate intracellular pathogens occupy one of two niches - free in the host cell cytoplasm or confined in a membrane-bound vacuole. Pathogens occupying membrane-bound vacuoles are sequestered from the innate immune system and have an extra layer of protection from antimicrobial drugs. However, this lifestyle presents several challenges. First, the bacteria must obtain membrane or membrane components to support vacuole expansion and provide space for the increasing bacteria numbers during the log phase of replication. Second, the vacuole microenvironment must be suitable for the unique metabolic needs of the pathogen. Third, as most obligate intracellular bacterial pathogens have undergone genomic reduction and are not capable of full metabolic independence, the bacteria must have mechanisms to obtain essential nutrients and resources from the host cell. Finally, because they are separated from the host cell by the vacuole membrane, the bacteria must possess mechanisms to manipulate the host cell, typically through a specialized secretion system which crosses the vacuole membrane. While there are common themes, each bacterial pathogen utilizes unique approach to establishing and maintaining their intracellular niches. In this review, we focus on the vacuole-bound intracellular niches of Anaplasma phagocytophilum, Ehrlichia chaffeensis, Chlamydia trachomatis, and Coxiella burnetii.
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Affiliation(s)
| | | | - Stacey D. Gilk
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
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Jorgenson LM, Knight L, Widner RE, Rucks EA. Eukaryotic Clathrin Adapter Protein and Mediator of Cholesterol Homeostasis, PICALM, Affects Trafficking to the Chlamydial Inclusion. Mol Cell Biol 2023; 43:1-13. [PMID: 36779337 PMCID: PMC9980547 DOI: 10.1080/10985549.2023.2171695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/19/2022] [Accepted: 01/16/2023] [Indexed: 02/14/2023] Open
Abstract
The obligate intracellular pathogen Chlamydia trachomatis has unique metabolic requirements as it proceeds through its biphasic developmental cycle from within the inclusion within the host cell. In our previous study, we identified a host protein, PICALM, which localizes to the chlamydial inclusion. PICALM functions in many host pathways including the recycling of receptors, specific SNARE proteins, and molecules like transferrin, and maintaining cholesterol homeostasis. Hence, we hypothesized that PICALM functions to maintain the cholesterol content and to moderate trafficking from the endosomal recycling pathway to the inclusion, which controls chlamydial access to this pathway. In uninfected cells, siRNA knockdown of PICALM resulted in increased cholesterol within the Golgi and transferrin receptor (TfR) positive vesicles (recycling endosomes). PICALM knockdown in cells infected with C. trachomatis resulted in increased levels of Golgi-derived lipid and protein, TfR, transferrin, and Rab11-FIP1 localized to inclusions and a decrease of Golgi fragmentation at and Rab11 trafficking to the inclusion. Interestingly, chlamydial infection alone also increases cholesterol in TfR and Rab11-associated vesicles, and PICALM knockdown reverses this effect. Our data suggest that PICALM functions to balance or limit chlamydial access to multiple subcellular trafficking pathways to maintain the health of the host cell during chlamydial infection.
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Affiliation(s)
- Lisa M. Jorgenson
- UNeMed Corporation, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Lindsey Knight
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Ray E. Widner
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Elizabeth A. Rucks
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Mayavannan A, Shantz E, Haidl ID, Wang J, Marshall JS. Mast cells selectively produce inflammatory mediators and impact the early response to Chlamydia reproductive tract infection. Front Immunol 2023; 14:1166068. [PMID: 37138882 PMCID: PMC10150091 DOI: 10.3389/fimmu.2023.1166068] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 03/28/2023] [Indexed: 05/05/2023] Open
Abstract
Introduction Chlamydia trachomatis (C. trachomatis) is a Gram-negative obligate intracellular bacterium that causes reproductive tract complications in women, including ectopic pregnancies and tubal factor infertility. We hypothesized that mast cells, which are common at mucosal barriers, may contribute to responses to Chlamydia infection and aimed to define human mast cell responses to C. trachomatis. Methods Human cord blood-derived mast cells (CBMCs) were exposed to C. trachomatis to assess bacterial uptake, mast cell degranulation, gene expression, and production of inflammatory mediators. The role of formyl peptide receptors and Toll-like receptor 2 (TLR2) were investigated using pharmacological inhibitors and soluble TLR2. Mast cell-deficient mice and littermate controls were used to examine the in vivo role of mast cells in influencing the immune response to Chlamydia infection in the female reproductive tract. Results C. trachomatis bacteria were taken up by human mast cells but did not replicate efficiently inside CBMCs. C. trachomatis-activated mast cells did not degranulate but maintained viability and exhibited cellular activation with homotypic aggregation and upregulation of ICAM-1. However, they significantly enhanced the gene expression of IL1B, CCL3, NFKB1, CXCL8, and IL6. Inflammatory mediators were produced, including TNF, IL-1β, IL-1RA, IL-6, GM-CSF, IL-23, CCL3, CCL5, and CXCL8. Endocytic blockade resulted in reduced gene expression of IL6, IL1B, and CCL3, suggesting C. trachomatis induced mast cell activation in both extracellular and intracellular locations. The IL-6 response to C. trachomatis was reduced when CBMCs were treated with C. trachomatis coated with soluble TLR2. Mast cells derived from TLR2-deficient mice also demonstrated a reduced IL-6 response to C. muridarum. Five days following C. muridarum infection, mast cell-deficient mice showed attenuated CXCL2 production and significantly reduced numbers of neutrophils, eosinophils, and B cells in the reproductive tract when compared with mast cell-containing littermates. Discussion Taken together, these data demonstrate that mast cells are reactive to Chlamydia spp. through multiple mechanisms that include TLR2-dependent pathways. Mast cells also play an important role in shaping in vivo immune responses in Chlamydia reproductive tract infection through both effector cell recruitment and modification of the chemokine microenvironment.
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Affiliation(s)
- Animamalar Mayavannan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Emily Shantz
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Ian D. Haidl
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Jun Wang
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
- Canadian Center for Vaccinology, Izaak Walton Killam (IWK) Health Centre, Halifax, NS, Canada
| | - Jean S. Marshall
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
- Department of Pathology, Dalhousie University, Halifax, NS, Canada
- *Correspondence: Jean S. Marshall,
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Godlee C, Holden DW. Transmembrane substrates of type three secretion system injectisomes. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001292. [PMID: 36748571 PMCID: PMC9993115 DOI: 10.1099/mic.0.001292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The type three secretion system injectisome of Gram-negative bacterial pathogens injects virulence proteins, called effectors, into host cells. Effectors of mammalian pathogens carry out a range of functions enabling bacterial invasion, replication, immune suppression and transmission. The injectisome secretes two translocon proteins that insert into host cell membranes to form a translocon pore, through which effectors are delivered. A subset of effectors also integrate into infected cell membranes, enabling a unique range of biochemical functions. Both translocon proteins and transmembrane effectors avoid cytoplasmic aggregation and integration into the bacterial inner membrane. Translocated transmembrane effectors locate and integrate into the appropriate host membrane. In this review, we focus on transmembrane translocon proteins and effectors of bacterial pathogens of mammals. We discuss what is known about the mechanisms underlying their membrane integration, as well as the functions conferred by the position of injectisome effectors within membranes.
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Affiliation(s)
- Camilla Godlee
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, London SW7 2AZ, UK
- Present address: Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
- *Correspondence: Camilla Godlee, ;
| | - David W. Holden
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, London SW7 2AZ, UK
- *Correspondence: David W. Holden,
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7
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Dolat L, Carpenter VK, Chen YS, Suzuki M, Smith EP, Kuddar O, Valdivia RH. Chlamydia repurposes the actin-binding protein EPS8 to disassemble epithelial tight junctions and promote infection. Cell Host Microbe 2022; 30:1685-1700.e10. [PMID: 36395759 PMCID: PMC9793342 DOI: 10.1016/j.chom.2022.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 08/08/2022] [Accepted: 10/21/2022] [Indexed: 11/17/2022]
Abstract
Invasive microbial pathogens often disrupt epithelial barriers, yet the mechanisms used to dismantle tight junctions are poorly understood. Here, we show that the obligate pathogen Chlamydia trachomatis uses the effector protein TepP to transiently disassemble tight junctions early during infection. TepP alters the tyrosine phosphorylation status of host proteins involved in cytoskeletal regulation, including the filamentous actin-binding protein EPS8. We determined that TepP and EPS8 are necessary and sufficient to remodel tight junctions and that the ensuing disruption of epithelial barrier function promotes secondary invasion events. The genetic deletion of EPS8 renders epithelial cells and endometrial organoids resistant to TepP-mediated tight junction remodeling. Finally, TepP and EPS8 promote infection in murine models of infections, with TepP mutants displaying defects in ascension to the upper genital tract. These findings reveal a non-canonical function of EPS8 in the disassembly of epithelial junctions and an important role for Chlamydia pathogenesis.
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Affiliation(s)
- Lee Dolat
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Victoria K Carpenter
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yi-Shan Chen
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michitaka Suzuki
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Erin P Smith
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ozge Kuddar
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Raphael H Valdivia
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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Khvotchev M, Soloviev M. SNARE Modulators and SNARE Mimetic Peptides. Biomolecules 2022; 12:biom12121779. [PMID: 36551207 PMCID: PMC9776023 DOI: 10.3390/biom12121779] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/22/2022] [Accepted: 11/26/2022] [Indexed: 12/03/2022] Open
Abstract
The soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (SNAP) receptor (SNARE) proteins play a central role in most forms of intracellular membrane trafficking, a key process that allows for membrane and biocargo shuffling between multiple compartments within the cell and extracellular environment. The structural organization of SNARE proteins is relatively simple, with several intrinsically disordered and folded elements (e.g., SNARE motif, N-terminal domain, transmembrane region) that interact with other SNAREs, SNARE-regulating proteins and biological membranes. In this review, we discuss recent advances in the development of functional peptides that can modify SNARE-binding interfaces and modulate SNARE function. The ability of the relatively short SNARE motif to assemble spontaneously into stable coiled coil tetrahelical bundles has inspired the development of reduced SNARE-mimetic systems that use peptides for biological membrane fusion and for making large supramolecular protein complexes. We evaluate two such systems, based on peptide-nucleic acids (PNAs) and coiled coil peptides. We also review how the self-assembly of SNARE motifs can be exploited to drive on-demand assembly of complex re-engineered polypeptides.
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Affiliation(s)
- Mikhail Khvotchev
- Department of Biochemistry, Center for Neuroscience, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Correspondence: (M.K.); (M.S.)
| | - Mikhail Soloviev
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
- Correspondence: (M.K.); (M.S.)
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Cournoyer JE, Altman SD, Gao YL, Wallace CL, Zhang D, Lo GH, Haskin NT, Mehta AP. Engineering artificial photosynthetic life-forms through endosymbiosis. Nat Commun 2022; 13:2254. [PMID: 35474066 PMCID: PMC9042829 DOI: 10.1038/s41467-022-29961-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/08/2022] [Indexed: 12/28/2022] Open
Abstract
The evolutionary origin of the photosynthetic eukaryotes drastically altered the evolution of complex lifeforms and impacted global ecology. The endosymbiotic theory suggests that photosynthetic eukaryotes evolved due to endosymbiosis between non-photosynthetic eukaryotic host cells and photosynthetic cyanobacterial or algal endosymbionts. The photosynthetic endosymbionts, propagating within the cytoplasm of the host cells, evolved, and eventually transformed into chloroplasts. Despite the fundamental importance of this evolutionary event, we have minimal understanding of this remarkable evolutionary transformation. Here, we design and engineer artificial, genetically tractable, photosynthetic endosymbiosis between photosynthetic cyanobacteria and budding yeasts. We engineer various mutants of model photosynthetic cyanobacteria as endosymbionts within yeast cells where, the engineered cyanobacteria perform bioenergetic functions to support the growth of yeast cells under defined photosynthetic conditions. We anticipate that these genetically tractable endosymbiotic platforms can be used for evolutionary studies, particularly related to organelle evolution, and also for synthetic biology applications. The endosymbiotic theory posits that chloroplasts in eukaryotes arise from bacterial endosymbionts. Here, the authors engineer the yeast/cyanobacteria chimeras and show that the engineered cyanobacteria perform chloroplast-like functions to support the growth of yeast cells under photosynthetic conditions.
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Affiliation(s)
- Jason E Cournoyer
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, Urbana, IL, 61801, USA
| | - Sarah D Altman
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, Urbana, IL, 61801, USA
| | - Yang-le Gao
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, Urbana, IL, 61801, USA
| | - Catherine L Wallace
- The Imaging Technology Group, Beckman Institute for Advanced Science & Technology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL, 61801, USA
| | - Dianwen Zhang
- The Imaging Technology Group, Beckman Institute for Advanced Science & Technology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL, 61801, USA
| | - Guo-Hsuen Lo
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, Urbana, IL, 61801, USA
| | - Noah T Haskin
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, Urbana, IL, 61801, USA
| | - Angad P Mehta
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, Urbana, IL, 61801, USA.
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10
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Garvin LE, DeBoer AG, Carrell SJ, Wang X, Rockey DD. Microscopic Analysis of the Chlamydia abortus Inclusion and Its Interaction with Those Formed by Other Chlamydial Species. Infect Immun 2022; 90:e0049921. [PMID: 35099268 PMCID: PMC8929342 DOI: 10.1128/iai.00499-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/18/2022] [Indexed: 11/20/2022] Open
Abstract
The Chlamydiae are obligate intracellular pathogens that develop and multiply within a poorly characterized parasitophorous vacuole (the inclusion) during growth. Chlamydia abortus is a major pathogen of sheep and other ruminants, and its inclusion development is poorly characterized. We used immunofluorescence microscopy, quantitative culture, and qPCR to examine C. abortus inclusion development and to examine the interaction of C. abortus inclusions with those formed by other species. Antibodies used in these studies include sera from ewes from production facilities that were naturally infected with C. abortus. Multiple inclusions are often found in C. abortus-infected cells, even in populations infected at very low multiplicity of infection. Labeling of fixed cells with sera from infected sheep revealed fibrous structures that extend away from the inclusion into the cytoplasm of the host cell. C. abortus inclusions fused with C. caviae and C. psittaci inclusions in coinfected cells. Inclusions formed by C. abortus and C. caviae did not fuse with inclusions formed by C. trachomatis, C. pneumoniae, or C. pecorum. The ability of inclusions to fuse was correlated with the overall genomic relatedness between species, and with sequence similarity in the inclusion membrane protein IncA. Quantitative PCR data demonstrated that C. abortus grows at a decreased rate during coinfections with C. caviae, while C. caviae growth was unaffected. The collected data add depth to our understanding of inclusion development in this significant zoonotic veterinary pathogen.
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Affiliation(s)
- Lotisha E. Garvin
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Addison G. DeBoer
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Steven J. Carrell
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Xisheng Wang
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Daniel D. Rockey
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
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11
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The Chlamydia trachomatis inclusion membrane protein CT006 associates with lipid droplets in eukaryotic cells. PLoS One 2022; 17:e0264292. [PMID: 35192658 PMCID: PMC8863265 DOI: 10.1371/journal.pone.0264292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/07/2022] [Indexed: 11/19/2022] Open
Abstract
Chlamydia trachomatis causes genital and ocular infections in humans. This bacterial pathogen multiplies exclusively within host cells in a characteristic vacuole (inclusion) and delivers proteins such as inclusion membrane proteins (Incs) into the host cell. Here, we identified CT006 as a novel C. trachomatis protein that when expressed ectopically eukaryotic cells can associate with lipid droplets (LDs). A screen using Saccharomyces cerevisiae identified two Incs causing vacuolar protein sorting defects and seven Incs showing tropism for eukaryotic organelles. Ectopic expression in yeast and mammalian cells of genes encoding different fragments of CT006 revealed tropism for the endoplasmic reticulum and LDs. We identified a LD-targeting region within the first 88 amino acid residues of CT006, and positively charged residues important for this targeting. Comparing with the parental wild-type strain, cells infected by a newly generated C. trachomatis strain overproducing CT006 with a double hemagglutinin tag showed a slight increase in the area occupied by LDs within the inclusion region. However, we could not correlate this effect with the LD-targeting regions within CT006. We further showed that both the amino and carboxy-terminal regions of CT006, flanking the Inc-characteristic bilobed hydrophobic domain, are exposed to the host cell cytosol during C. trachomatis infection, supporting their availability to interact with host cell targets. Altogether, our data suggest that CT006 might participate in the interaction of LDs with C. trachomatis inclusions.
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12
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VAMP3 and VAMP8 regulate the development and functionality of parasitophorous vacuoles housing Leishmania amazonensis. Infect Immun 2022; 90:e0018321. [PMID: 35130453 DOI: 10.1128/iai.00183-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To colonize mammalian phagocytic cells, the parasite Leishmania remodels phagosomes into parasitophorous vacuoles that can be either tight-fitting individual or communal. The molecular and cellular bases underlying the biogenesis and functionality of these two types of vacuoles are poorly understood. In this study, we investigated the contribution of host cell Soluble N-ethylmaleimide-sensitive-factor Attachment protein REceptor proteins to the expansion and functionality of communal vacuoles as well as on the replication of the parasite. The differential recruitment patterns of Soluble N-ethylmaleimide-sensitive-factor Attachment protein REceptor to communal vacuoles harboring L. amazonensis and to individual vacuoles housing L. major led us to further investigate the roles of VAMP3 and VAMP8 in the interaction of Leishmania with its host cell. We show that whereas VAMP8 contributes to optimal expansion of communal vacuoles, VAMP3 negatively regulates L. amazonensis replication, vacuole size, as well as antigen cross-presentation. In contrast, neither proteins has an impact on the fate of L. major. Collectively, our data support a role for both VAMP3 and VAMP8 in the development and functionality of L. amazonensis-harboring communal parasitophorous vacuoles.
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13
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Jorgenson LM, Olson-Wood MG, Rucks EA. Shifting proteomes: limitations in using the BioID proximity labeling system to study SNARE protein trafficking during infection with intracellular pathogens. Pathog Dis 2021; 79:ftab039. [PMID: 34323972 PMCID: PMC8379010 DOI: 10.1093/femspd/ftab039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 07/25/2021] [Indexed: 11/12/2022] Open
Abstract
We hypothesize that intracellular trafficking pathways are altered in chlamydial infected cells to maximize the ability of Chlamydia to scavenge nutrients while not overtly stressing the host cell. Previous data demonstrated the importance of two eukaryotic SNARE proteins, VAMP4 and syntaxin 10 (Stx10), in chlamydial growth and development. Although, the mechanism for these effects is still unknown. To interrogate whether chlamydial infection altered these proteins' networks, we created BirA*-VAMP4 and BirA*-Stx10 fusion constructs to use the BioID proximity labeling system. While we identified a novel eukaryotic protein-protein interaction between Stx10 and VAPB, we also identified caveats in using the BioID system to study the impact of infection by an obligate intracellular pathogen on SNARE protein networks. The addition of the BirA* altered the localization of VAMP4 and Stx10 during infection with Chlamydia trachomatis serovars L2 and D and Coxiella burnetii Nine Mile Phase II. We also discovered that BirA* traffics to and biotinylates Coxiella-containing vacuoles and, in general, has a propensity for labeling membrane or membrane-associated proteins. While the BioID system identified a novel association for Stx10, it is not a reliable methodology to examine intracellular trafficking pathway dynamics during infection with intracellular pathogens.
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Affiliation(s)
- Lisa M Jorgenson
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Durham Research Center II, 985900 Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Macy G Olson-Wood
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Durham Research Center II, 985900 Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Elizabeth A Rucks
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Durham Research Center II, 985900 Nebraska Medical Center, Omaha, NE 68198-5900, USA
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14
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Andersen SE, Bulman LM, Steiert B, Faris R, Weber MM. Got mutants? How advances in chlamydial genetics have furthered the study of effector proteins. Pathog Dis 2021; 79:ftaa078. [PMID: 33512479 PMCID: PMC7862739 DOI: 10.1093/femspd/ftaa078] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/17/2020] [Indexed: 02/07/2023] Open
Abstract
Chlamydia trachomatis is the leading cause of infectious blindness and a sexually transmitted infection. All chlamydiae are obligate intracellular bacteria that replicate within a membrane-bound vacuole termed the inclusion. From the confines of the inclusion, the bacteria must interact with many host organelles to acquire key nutrients necessary for replication, all while promoting host cell viability and subverting host defense mechanisms. To achieve these feats, C. trachomatis delivers an arsenal of virulence factors into the eukaryotic cell via a type 3 secretion system (T3SS) that facilitates invasion, manipulation of host vesicular trafficking, subversion of host defense mechanisms and promotes bacteria egress at the conclusion of the developmental cycle. A subset of these proteins intercalate into the inclusion and are thus referred to as inclusion membrane proteins. Whereas others, referred to as conventional T3SS effectors, are released into the host cell where they localize to various eukaryotic organelles or remain in the cytosol. Here, we discuss the functions of T3SS effector proteins with a focus on how advances in chlamydial genetics have facilitated the identification and molecular characterization of these important factors.
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Affiliation(s)
- Shelby E Andersen
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Lanci M Bulman
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Brianna Steiert
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Robert Faris
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Mary M Weber
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
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15
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Eukaryotic SNARE VAMP3 Dynamically Interacts with Multiple Chlamydial Inclusion Membrane Proteins. Infect Immun 2021; 89:IAI.00409-20. [PMID: 33229367 PMCID: PMC7822134 DOI: 10.1128/iai.00409-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 11/15/2020] [Indexed: 01/13/2023] Open
Abstract
Chlamydia trachomatis, an obligate intracellular pathogen, undergoes a biphasic developmental cycle within a membrane-bound vacuole called the chlamydial inclusion. To facilitate interactions with the host cell, Chlamydia modifies the inclusion membrane with type III secreted proteins, called Incs. Chlamydia trachomatis, an obligate intracellular pathogen, undergoes a biphasic developmental cycle within a membrane-bound vacuole called the chlamydial inclusion. To facilitate interactions with the host cell, Chlamydia modifies the inclusion membrane with type III secreted proteins, called Incs. As with all chlamydial proteins, Incs are temporally expressed, modifying the chlamydial inclusion during the early and mid-developmental cycle. VAMP3 and VAMP4 are eukaryotic SNARE proteins that mediate membrane fusion and are recruited to the inclusion to facilitate inclusion expansion. Their recruitment requires de novo chlamydial protein synthesis during the mid-developmental cycle. Thus, we hypothesize that VAMP3 and VAMP4 are recruited by Incs. In chlamydia-infected cells, identifying Inc binding partners for SNARE proteins specifically has been elusive. To date, most studies examining chlamydial Inc and eukaryotic proteins have benefitted from stable interacting partners or a robust interaction at a specific time postinfection. While these types of interactions are the predominant class that have been identified, they are likely the exception to chlamydia-host interactions. Therefore, we applied two separate but complementary experimental systems to identify candidate chlamydial Inc binding partners for VAMPs. Based on these results, we created transformed strains of C. trachomatis serovar L2 to inducibly express a candidate Inc-FLAG protein. In chlamydia-infected cells, we found that five Incs temporally and transiently interact with VAMP3. Further, loss of incA or ct813 expression altered VAMP3 localization to the inclusion. For the first time, our studies demonstrate the transient nature of certain host protein-Inc interactions that contribute to the chlamydial developmental cycle.
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16
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Stévenin V, Chang YY, Le Toquin Y, Duchateau M, Gianetto QG, Luk CH, Salles A, Sohst V, Matondo M, Reiling N, Enninga J. Dynamic Growth and Shrinkage of the Salmonella-Containing Vacuole Determines the Intracellular Pathogen Niche. Cell Rep 2020; 29:3958-3973.e7. [PMID: 31851926 PMCID: PMC6931108 DOI: 10.1016/j.celrep.2019.11.049] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/23/2019] [Accepted: 11/12/2019] [Indexed: 12/21/2022] Open
Abstract
Salmonella is a human and animal pathogen that causes gastro-enteric diseases. The key to Salmonella infection is its entry into intestinal epithelial cells, where the bacterium resides within a Salmonella-containing vacuole (SCV). Salmonella entry also induces the formation of empty macropinosomes, distinct from the SCV, in the vicinity of the entering bacteria. A few minutes after its formation, the SCV increases in size through fusions with the surrounding macropinosomes. Salmonella also induces membrane tubules that emanate from the SCV and lead to SCV shrinkage. Here, we show that these antipodal events are utilized by Salmonella to either establish a vacuolar niche or to be released into the cytosol by SCV rupture. We identify the molecular machinery underlying dynamic SCV growth and shrinkage. In particular, the SNARE proteins SNAP25 and STX4 participate in SCV inflation by fusion with macropinosomes. Thus, host compartment size control emerges as a pathogen strategy for intracellular niche regulation. The early SCV simultaneously grows and shrinks through fusion and tubule formation SCV shrinkage promotes vacuolar rupture and cytosolic release IAMs are enriched in the host SNAREs SNAP25 and STX4, enabling IAM-SCV fusion Promoting SNX1-mediated tubule formation, SopB fosters SCV ruptures
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Affiliation(s)
- Virginie Stévenin
- Institut Pasteur, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, Paris, France
| | - Yuen-Yan Chang
- Institut Pasteur, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, Paris, France
| | - Yoann Le Toquin
- Institut Pasteur, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, Paris, France
| | - Magalie Duchateau
- Institut Pasteur, Plateforme Protéomique, Unité de Spectrométrie de Masse pour la Biologie, C2RT, USR 2000 CNRS, Paris, France
| | - Quentin Giai Gianetto
- Institut Pasteur, Plateforme Protéomique, Unité de Spectrométrie de Masse pour la Biologie, C2RT, USR 2000 CNRS, Paris, France; Institut Pasteur, Bioinformatics and Biostatistics HUB, C3BI, USR CNRS 3756, Paris, France
| | - Chak Hon Luk
- Institut Pasteur, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, Paris, France
| | - Audrey Salles
- Institut Pasteur, UtechS Photonic BioImaging PBI (Imagopole), Centre de Recherche et de Ressources Technologiques C2RT, Paris, France
| | - Victoria Sohst
- Research Center Borstel, Leibniz Lung Center, RG Microbial Interface Biology, Parkallee 22, 23845 Borstel, Germany
| | - Mariette Matondo
- Institut Pasteur, Plateforme Protéomique, Unité de Spectrométrie de Masse pour la Biologie, C2RT, USR 2000 CNRS, Paris, France
| | - Norbert Reiling
- Research Center Borstel, Leibniz Lung Center, RG Microbial Interface Biology, Parkallee 22, 23845 Borstel, Germany; German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Borstel, Germany
| | - Jost Enninga
- Institut Pasteur, Dynamics of Host-Pathogen Interactions Unit, 25 Rue du Dr. Roux, Paris, France.
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17
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Faris R, Merling M, Andersen SE, Dooley CA, Hackstadt T, Weber MM. Chlamydia trachomatis CT229 Subverts Rab GTPase-Dependent CCV Trafficking Pathways to Promote Chlamydial Infection. Cell Rep 2020; 26:3380-3390.e5. [PMID: 30893609 DOI: 10.1016/j.celrep.2019.02.079] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/28/2018] [Accepted: 02/20/2019] [Indexed: 01/25/2023] Open
Abstract
Chlamydial infection requires the formation of a membrane-bound vacuole, termed the inclusion, that undergoes extensive interactions with select host organelles. The importance of the Inc protein CT229 in the formation and maintenance of the chlamydial inclusion was recently highlighted by studies demonstrating that its absence during infection results in reduced bacterial replication, premature inclusion lysis, and host cell death. Previous reports have indicated that CT229 binds Rab GTPases; however, the physiological implications of this interaction are unknown. Here, we show that CT229 regulates host multivesicular trafficking by recruiting multiple Rab GTPases and their cognate effectors to the inclusion. We demonstrate that CT229 specifically modulates clathrin-coated vesicle trafficking and regulates the trafficking of transferrin and the mannose-6-phosphate receptor, both of which are crucial for proper chlamydial development. This study highlights CT229 as a master regulator of multiple host vesicular trafficking pathways essential for chlamydial infection.
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Affiliation(s)
- Robert Faris
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Marlena Merling
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Department of Biology, University of Dayton, Dayton, OH 45469, USA
| | - Shelby E Andersen
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Cheryl A Dooley
- Host Parasite Interactions Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Disease, NIH, Hamilton, MT 59840, USA
| | - Ted Hackstadt
- Host Parasite Interactions Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Disease, NIH, Hamilton, MT 59840, USA
| | - Mary M Weber
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
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18
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A predation assay using amoebae to screen for virulence factors unearthed the first W. chondrophila inclusion membrane protein. Sci Rep 2019; 9:19485. [PMID: 31862969 PMCID: PMC6925127 DOI: 10.1038/s41598-019-55511-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 11/11/2019] [Indexed: 01/21/2023] Open
Abstract
Waddlia chondrophila is an intracellular bacterium phylogenetically related to the well-studied human and animal pathogens of the Chlamydiaceae family. In the last decade, W. chondrophila was convincingly demonstrated to be associated with adverse pregnancy outcomes in humans and abortions in animals. All members of the phylum Chlamydiae possess a Type Three Secretion System that they use for delivering virulence proteins into the host cell cytosol to modulate their environment and create optimal conditions to complete their life cycle. To identify W. chondrophila virulence proteins, we used an original screening approach that combines a cosmid library with an assay monitoring resistance to predation by phagocytic amoebae. This technique combined with bioinformatic data allowed the identification of 28 candidate virulence proteins, including Wimp1, the first identified inclusion membrane protein of W. chondrophila.
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19
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Proximity Labeling To Map Host-Pathogen Interactions at the Membrane of a Bacterium-Containing Vacuole in Chlamydia trachomatis-Infected Human Cells. Infect Immun 2019; 87:IAI.00537-19. [PMID: 31405957 PMCID: PMC6803327 DOI: 10.1128/iai.00537-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 08/06/2019] [Indexed: 02/06/2023] Open
Abstract
Many intracellular bacteria, including the obligate intracellular pathogen Chlamydia trachomatis, grow within a membrane-bound bacterium-containing vacuole (BCV). Secreted cytosolic effectors modulate host activity, but an understanding of the host-pathogen interactions that occur at the BCV membrane is limited by the difficulty in purifying membrane fractions from infected host cells. Many intracellular bacteria, including the obligate intracellular pathogen Chlamydia trachomatis, grow within a membrane-bound bacterium-containing vacuole (BCV). Secreted cytosolic effectors modulate host activity, but an understanding of the host-pathogen interactions that occur at the BCV membrane is limited by the difficulty in purifying membrane fractions from infected host cells. We used the ascorbate peroxidase (APEX2) proximity labeling system, which labels proximal proteins with biotin in vivo, to study the protein-protein interactions that occur at the chlamydial vacuolar, or inclusion, membrane. An in vivo understanding of the secreted chlamydial inclusion membrane protein (Inc) interactions (e.g., Inc-Inc and Inc-eukaryotic protein) and how these contribute to overall host-chlamydia interactions at this unique membrane is lacking. We hypothesize some Incs organize the inclusion membrane, whereas other Incs bind eukaryotic proteins to promote chlamydia-host interactions. To study this, Incs fused to APEX2 were expressed in C. trachomatis L2. Affinity purification-mass spectrometry (AP-MS) identified biotinylated proteins, which were analyzed for statistical significance using significance analysis of the interactome (SAINT). Broadly supporting both Inc-Inc and Inc-host interactions, our Inc-APEX2 constructs labeled Incs as well as known and previously unreported eukaryotic proteins localizing to the inclusion. We demonstrate, using bacterial two-hybrid and coimmunoprecipitation assays, that endogenous LRRFIP1 (LRRF1) is recruited to the inclusion by the Inc CT226. We further demonstrate interactions between CT226 and the Incs used in our study to reveal a model for inclusion membrane organization. Combined, our data highlight the utility of APEX2 to capture the complex in vivo protein-protein interactions at the chlamydial inclusion.
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20
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Gitsels A, Sanders N, Vanrompay D. Chlamydial Infection From Outside to Inside. Front Microbiol 2019; 10:2329. [PMID: 31649655 PMCID: PMC6795091 DOI: 10.3389/fmicb.2019.02329] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Chlamydia are obligate intracellular bacteria, characterized by a unique biphasic developmental cycle. Specific interactions with the host cell are crucial for the bacteria’s survival and amplification because of the reduced chlamydial genome. At the start of infection, pathogen-host interactions are set in place in order for Chlamydia to enter the host cell and reach the nutrient-rich peri-Golgi region. Once intracellular localization is established, interactions with organelles and pathways of the host cell enable the necessary hijacking of host-derived nutrients. Detailed information on the aforementioned processes will increase our understanding on the intracellular pathogenesis of chlamydiae and hence might lead to new strategies to battle chlamydial infection. This review summarizes how chlamydiae generate their intracellular niche in the host cell, acquire host-derived nutrients in order to enable their growth and finally exit the host cell in order to infect new cells. Moreover, the evolution in the development of molecular genetic tools, necessary for studying the chlamydial infection biology in more depth, is discussed in great detail.
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Affiliation(s)
- Arlieke Gitsels
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Niek Sanders
- Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Daisy Vanrompay
- Laboratory for Immunology and Animal Biotechnology, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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21
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Mehta AP, Ko Y, Supekova L, Pestonjamasp K, Li J, Schultz PG. Toward a Synthetic Yeast Endosymbiont with a Minimal Genome. J Am Chem Soc 2019; 141:13799-13802. [PMID: 31419116 DOI: 10.1021/jacs.9b08290] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Based on the endosymbiotic theory, one of the key events that occurred during mitochondrial evolution was an extensive loss of nonessential genes from the protomitochondrial endosymbiont genome and transfer of some of the essential endosymbiont genes to the host nucleus. We have developed an approach to recapitulate various aspects of endosymbiont genome minimization using a synthetic system consisting of Escherichia coli endosymbionts within host yeast cells. As a first step, we identified a number of E. coli auxotrophs of central metabolites that can form viable endosymbionts within yeast cells. These studies provide a platform to identify nonessential biosynthetic pathways that can be deleted in the E. coli endosymbionts to investigate the evolutionary adaptations in the host and endosymbiont during the evolution of mitochondria.
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Affiliation(s)
- Angad P Mehta
- The Department of Chemistry , Scripps Research , La Jolla , California 92037 , United States
| | - Yeonjin Ko
- The Department of Chemistry , Scripps Research , La Jolla , California 92037 , United States
| | - Lubica Supekova
- The Department of Chemistry , Scripps Research , La Jolla , California 92037 , United States
| | - Kersi Pestonjamasp
- The Core Microscopy Facility , Scripps Research , La Jolla , California 92037 , United States
| | - Jack Li
- The Department of Chemistry , Scripps Research , La Jolla , California 92037 , United States
| | - Peter G Schultz
- The Department of Chemistry , Scripps Research , La Jolla , California 92037 , United States
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22
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Bugalhão JN, Mota LJ. The multiple functions of the numerous Chlamydia trachomatis secreted proteins: the tip of the iceberg. MICROBIAL CELL 2019; 6:414-449. [PMID: 31528632 PMCID: PMC6717882 DOI: 10.15698/mic2019.09.691] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Chlamydia trachomatis serovars are obligate intracellular bacterial pathogens mainly causing ocular and urogenital infections that affect millions of people worldwide and which can lead to blindness or sterility. They reside and multiply intracellularly within a membrane-bound vacuolar compartment, known as inclusion, and are characterized by a developmental cycle involving two morphologically and physiologically distinct chlamydial forms. Completion of the developmental cycle involves the secretion of > 70 C. trachomatis proteins that function in the host cell cytoplasm and nucleus, in the inclusion membrane and lumen, and in the extracellular milieu. These proteins can, for example, interfere with the host cell cytoskeleton, vesicular and non-vesicular transport, metabolism, and immune signalling. Generally, this promotes C. trachomatis invasion into, and escape from, host cells, the acquisition of nutrients by the chlamydiae, and evasion of cell-autonomous, humoral and cellular innate immunity. Here, we present an in-depth review on the current knowledge and outstanding questions about these C. trachomatis secreted proteins.
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Affiliation(s)
- Joana N Bugalhão
- UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Luís Jaime Mota
- UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
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23
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Bioinformatic analysis suggests potential mechanisms underlying parasitoid venom evolution and function. Genomics 2019; 112:1096-1104. [PMID: 31247332 DOI: 10.1016/j.ygeno.2019.06.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 11/21/2022]
Abstract
Hymenopteran parasitoid wasps are a diverse collection of species that infect arthropod hosts and use factors found in their venoms to manipulate host immune responses, physiology, and behaviour. Whole parasitoid venoms have been profiled using proteomic approaches, and here we present a bioinformatic characterization of the venom protein content from Ganaspis sp. 1, a parasitoid that infects flies of the genus Drosophila. We find evidence that diverse evolutionary processes including multifunctionalization, co-option, gene duplication, and horizontal gene transfer may be acting in concert to drive venom gene evolution in Ganaspis sp.1. One major role of parasitoid wasp venom is host immune evasion. We previously demonstrated that Ganaspis sp. 1 venom inhibits immune cell activation in infected Drosophila melanogaster hosts, and our current analysis has uncovered additional predicted virulence functions. Overall, this analysis represents an important step towards understanding the composition and activity of parasitoid wasp venoms.
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24
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Make It a Sweet Home: Responses of Chlamydia trachomatis to the Challenges of an Intravacuolar Lifestyle. Microbiol Spectr 2019; 7. [PMID: 30848236 DOI: 10.1128/microbiolspec.bai-0005-2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Intravacuolar development has been adopted by several bacteria that grow inside a host cell. Remaining in a vacuole, as opposed to breaching the cytosol, protects the bacteria from some aspects of the cytosolic innate host defense and allows them to build an environment perfectly adapted to their needs. However, this raises new challenges: the host resources are separated from the bacteria by a lipid bilayer that is nonpermeable to most nutrients. In addition, the area of this lipid bilayer needs to expand to accommodate bacterial multiplication. This requires building material and energy that are not directly invested in bacterial growth. This article describes the strategies acquired by the obligate intracellular pathogen Chlamydia trachomatis to circumvent the difficulties raised by an intravacuolar lifestyle. We start with an overview of the origin and composition of the vacuolar membrane. Acquisition of host resources is largely, although not exclusively, mediated by interactions with membranous compartments of the eukaryotic cell, and we describe how the inclusion modifies the architecture of the cell and distribution of the neighboring compartments. The second part of this review describes the four mechanisms characterized so far by which the bacteria acquire resources from the host: (i) transport/diffusion across the vacuole membrane, (ii) fusion of this membrane with host compartments, (iii) direct transfer of lipids at membrane contact sites, and (iv) engulfment by the vacuole membrane of large cytoplasmic entities.
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25
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Olson MG, Jorgenson LM, Widner RE, Rucks EA. Proximity Labeling of the Chlamydia trachomatis Inclusion Membrane. Methods Mol Biol 2019; 2042:245-278. [PMID: 31385281 DOI: 10.1007/978-1-4939-9694-0_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In the study of intracellular bacteria that reside within a membrane-bound vacuole, there are many questions related to how prokaryotic or eukaryotic transmembrane or membrane-associated proteins are organized and function within the membranes of these pathogen-containing vacuoles. Yet this host-pathogen interaction interface has proven difficult to experimentally resolve. For example, one method to begin to understand protein function is to determine the protein-binding partners; however, examining protein-protein interactions of hydrophobic transmembrane proteins is not widely successful using standard immunoprecipitation or coimmunoprecipitation techniques. In these scenarios, the lysis conditions that maintain protein-protein interactions are not compatible with solubilizing hydrophobic membrane proteins. In this chapter, we outline two proximity labeling systems to circumvent these issues to study (1) eukaryotic proteins that localize to the membrane-bound inclusion formed by Chlamydia trachomatis using BioID, and (2) chlamydial proteins that are inserted into the inclusion membrane using APEX2. BioID is a promiscuous biotin ligase to tag proximal proteins with biotin. APEX2 is an ascorbate peroxidase that creates biotin-phenoxyl radicals to label proximal proteins with biotin or 3,3'-diaminobenzidine intermediates for examination of APEX2 labeling of subcellular structures using transmission electron microscopy. We present how these methods were originally conceptualized and developed, so that the user can understand the strengths and limitations of each proximity labeling system. We discuss important considerations regarding experimental design, which include careful consideration of background conditions and statistical analysis of mass spectrometry results. When applied in the appropriate context with adequate controls, these methods can be powerful tools toward understanding membrane interfaces between intracellular pathogens and their hosts.
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Affiliation(s)
- Macy G Olson
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Lisa M Jorgenson
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Ray E Widner
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Elizabeth A Rucks
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA.
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Martinez E, Siadous FA, Bonazzi M. Tiny architects: biogenesis of intracellular replicative niches by bacterial pathogens. FEMS Microbiol Rev 2018; 42:425-447. [PMID: 29596635 DOI: 10.1093/femsre/fuy013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 03/26/2018] [Indexed: 11/13/2022] Open
Abstract
Co-evolution of bacterial pathogens with their hosts led to the emergence of a stunning variety of strategies aiming at the evasion of host defences, colonisation of host cells and tissues and, ultimately, the establishment of a successful infection. Pathogenic bacteria are typically classified as extracellular and intracellular; however, intracellular lifestyle comes in many different flavours: some microbes rapidly escape to the cytosol whereas other microbes remain within vacuolar compartments and harness membrane trafficking pathways to generate their host-derived, pathogen-specific replicative niche. Here we review the current knowledge on a variety of vacuolar lifestyles, the effector proteins used by bacteria as tools to take control of the host cell and the main membrane trafficking signalling pathways targeted by vacuolar pathogens as source of membranes and nutrients. Finally, we will also discuss how host cells have developed countermeasures to sense the biogenesis of the aberrant organelles harbouring bacteria. Understanding the dialogue between bacterial and eukaryotic proteins is the key to unravel the molecular mechanisms of infection and in turn, this may lead to the identification of new targets for the development of new antimicrobials.
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Affiliation(s)
- Eric Martinez
- IRIM, University of Montpellier, CNRS, 34293 Montpellier, France
| | | | - Matteo Bonazzi
- IRIM, University of Montpellier, CNRS, 34293 Montpellier, France
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Shaw JH, Key CE, Snider TA, Sah P, Shaw EI, Fisher DJ, Lutter EI. Genetic Inactivation of Chlamydia trachomatis Inclusion Membrane Protein CT228 Alters MYPT1 Recruitment, Extrusion Production, and Longevity of Infection. Front Cell Infect Microbiol 2018; 8:415. [PMID: 30555802 PMCID: PMC6284022 DOI: 10.3389/fcimb.2018.00415] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 11/08/2018] [Indexed: 02/01/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular pathogen with global health and economic impact. Upon infection, C. trachomatis resides within a protective niche, the inclusion, wherein it replicates and usurps host cell machinery and resources. The inclusion membrane is the key host-pathogen interface that governs specific protein-protein interactions to manipulate host signaling pathways. At the conclusion of the infection cycle, C. trachomatis exits the host cell via lysis or extrusion. Extrusion depends on the phosphorylation state of myosin light chain 2 (MLC2); the extent of phosphorylation is determined by the ongoing opposing activities of myosin phosphatase (MYPT1) and myosin kinase (MLCK). Previously, it was shown that MYPT1 is recruited to the inclusion and interacts with CT228 for regulation of host cell egress. In this study, we generated a targeted chromosomal mutation of CT228 (L2-ΔCT228) using the TargeTron system and demonstrate a loss of MYPT1 recruitment and increase in extrusion production in vitro. Mutation of CT228 did not affect chlamydial growth in cell culture or recruitment of MLC2. Moreover, we document a delay in clearance of L2-ΔCT228 during murine intravaginal infection as well as a reduction in systemic humoral response, relative to L2-wild type. Taken together, the data suggest that loss of MYPT1 recruitment (as a result of CT228 disruption) regulates the degree of host cell exit via extrusion and affects the longevity of infection in vivo.
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Affiliation(s)
- Jennifer H. Shaw
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, United States,*Correspondence: Jennifer H. Shaw
| | - Charlotte E. Key
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, United States
| | - Timothy A. Snider
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK, United States
| | - Prakash Sah
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Edward I. Shaw
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Derek J. Fisher
- Department of Microbiology, Southern Illinois University, Carbondale, IL, United States
| | - Erika I. Lutter
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States,Erika I. Lutter
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28
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Engineering yeast endosymbionts as a step toward the evolution of mitochondria. Proc Natl Acad Sci U S A 2018; 115:11796-11801. [PMID: 30373839 DOI: 10.1073/pnas.1813143115] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It has been hypothesized that mitochondria evolved from a bacterial ancestor that initially became established in an archaeal host cell as an endosymbiont. Here we model this first stage of mitochondrial evolution by engineering endosymbiosis between Escherichia coli and Saccharomyces cerevisiae An ADP/ATP translocase-expressing E. coli provided ATP to a respiration-deficient cox2 yeast mutant and enabled growth of a yeast-E. coli chimera on a nonfermentable carbon source. In a reciprocal fashion, yeast provided thiamin to an endosymbiotic E. coli thiamin auxotroph. Expression of several SNARE-like proteins in E. coli was also required, likely to block lysosomal degradation of intracellular bacteria. This chimeric system was stable for more than 40 doublings, and GFP-expressing E. coli endosymbionts could be observed in the yeast by fluorescence microscopy and X-ray tomography. This readily manipulated system should allow experimental delineation of host-endosymbiont adaptations that occurred during evolution of the current, highly reduced mitochondrial genome.
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Singh PK, Kapoor A, Lomash RM, Kumar K, Kamerkar SC, Pucadyil TJ, Mukhopadhyay A. Salmonella SipA mimics a cognate SNARE for host Syntaxin8 to promote fusion with early endosomes. J Cell Biol 2018; 217:4199-4214. [PMID: 30309979 PMCID: PMC6279372 DOI: 10.1083/jcb.201802155] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 08/17/2018] [Accepted: 09/18/2018] [Indexed: 01/06/2023] Open
Abstract
Intracellular pathogens can modulate host Rabs and SNAREs to support their replication and immune evasion. Singh et al. show that the Salmonella effector SipA functionally mimics an R-SNARE and recruits host Q-SNAREs to promote membrane fusion. Thus, SNARE mimicry by this intracellular pathogen effector modulates the host trafficking machinery for Salmonella survival. SipA is a major effector of Salmonella, which causes gastroenteritis and enteric fever. Caspase-3 cleaves SipA into two domains: the C-terminal domain regulates actin polymerization, whereas the function of the N terminus is unknown. We show that the cleaved SipA N terminus binds and recruits host Syntaxin8 (Syn8) to Salmonella-containing vacuoles (SCVs). The SipA N terminus contains a SNARE motif with a conserved arginine residue like mammalian R-SNAREs. SipAR204Q and SipA1–435R204Q do not bind Syn8, demonstrating that SipA mimics a cognate R-SNARE for Syn8. Consequently, Salmonella lacking SipA or that express the SipA1–435R204Q SNARE mutant are unable to recruit Syn8 to SCVs. Finally, we show that SipA mimicking an R-SNARE recruits Syn8, Syn13, and Syn7 to the SCV and promotes its fusion with early endosomes to potentially arrest its maturation. Our results reveal that SipA functionally substitutes endogenous SNAREs in order to hijack the host trafficking pathway and promote Salmonella survival.
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Affiliation(s)
| | - Anjali Kapoor
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | | | - Kamal Kumar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
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30
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Genome-wide association meta-analysis of coronary artery disease and periodontitis reveals a novel shared risk locus. Sci Rep 2018; 8:13678. [PMID: 30209331 PMCID: PMC6135769 DOI: 10.1038/s41598-018-31980-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 08/31/2018] [Indexed: 02/07/2023] Open
Abstract
Evidence for a shared genetic basis of association between coronary artery disease (CAD) and periodontitis (PD) exists. To explore the joint genetic basis, we performed a GWAS meta-analysis. In the discovery stage, we used a German aggressive periodontitis sample (AgP-Ger; 680 cases vs 3,973 controls) and the CARDIoGRAMplusC4D CAD meta-analysis dataset (60,801 cases vs 123,504 controls). Two SNPs at the known CAD risk loci ADAMTS7 (rs11634042) and VAMP8 (rs1561198) passed the pre-assigned selection criteria (PAgP-Ger < 0.05; PCAD < 5 × 10−8; concordant effect direction) and were replicated in an independent GWAS meta-analysis dataset of PD (4,415 cases vs 5,935 controls). SNP rs1561198 showed significant association (PD[Replication]: P = 0.008 OR = 1.09, 95% CI = [1.02–1.16]; PD [Discovery + Replication]: P = 0.0002, OR = 1.11, 95% CI = [1.05–1.17]). For the associated haplotype block, allele specific cis-effects on VAMP8 expression were reported. Our data adds to the shared genetic basis of CAD and PD and indicate that the observed association of the two disease conditions cannot be solely explained by shared environmental risk factors. We conclude that the molecular pathway shared by CAD and PD involves VAMP8 function, which has a role in membrane vesicular trafficking, and is manipulated by pathogens to corrupt host immune defense.
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31
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Almeida F, Luís MP, Pereira IS, Pais SV, Mota LJ. The Human Centrosomal Protein CCDC146 Binds Chlamydia trachomatis Inclusion Membrane Protein CT288 and Is Recruited to the Periphery of the Chlamydia-Containing Vacuole. Front Cell Infect Microbiol 2018; 8:254. [PMID: 30094225 PMCID: PMC6070772 DOI: 10.3389/fcimb.2018.00254] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/04/2018] [Indexed: 01/12/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular human pathogen causing mainly ocular and genital infections of significant clinical and public health impact. C. trachomatis multiplies intracellularly in a membrane bound vacuole, known as inclusion. Both extracellularly and from within the inclusion, C. trachomatis uses a type III secretion system to deliver several effector proteins into the cytoplasm of host cells. A large proportion of these effectors, the inclusion membrane (Inc) proteins, are exposed to the host cell cytosol but possess a characteristic hydrophobic domain mediating their insertion in the inclusion membrane. By yeast two-hybrid, we found that C. trachomatis Inc CT288 interacts with the human centrosomal protein CCDC146 (coiled-coil domain-containing protein 146). The interaction was also detected by co-immunoprecipitation in mammalian cells either ectopically expressing CCDC146 and CT288 or ectopically expressing CCDC146 and infected by a C. trachomatis strain expressing epitope-tagged and inclusion membrane-localized CT288. In uninfected mammalian cells, ectopically expressed full-length CCDC146 (955 amino acid residues) localized at the centrosome; but in cells infected by wild-type C. trachomatis, its centrosomal localization was less evident and CCDC146 accumulated around the inclusion. Recruitment of CCDC146 to the inclusion periphery did not require intact host Golgi, microtubules or microfilaments, but was dependent on chlamydial protein synthesis. Full-length CCDC146 also accumulated at the periphery of the inclusion in cells infected by a C. trachomatis ct288 mutant; however, a C-terminal fragment of CCDC146 (residues 692–955), which interacts with CT288, showed differences in localization at the periphery of the inclusion in cells infected by wild-type or ct288 mutant C. trachomatis. This suggests a model in which chlamydial proteins other than CT288 recruit CCDC146 to the periphery of the inclusion, where the CT288-CCDC146 interaction might contribute to modulate the function of this host protein.
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Affiliation(s)
- Filipe Almeida
- Research Unit on Applied Molecular Biosciences (UCIBIO) - REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Costa da Caparica, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Maria P Luís
- Research Unit on Applied Molecular Biosciences (UCIBIO) - REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Costa da Caparica, Portugal
| | - Inês Serrano Pereira
- Research Unit on Applied Molecular Biosciences (UCIBIO) - REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Costa da Caparica, Portugal
| | - Sara V Pais
- Research Unit on Applied Molecular Biosciences (UCIBIO) - REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Costa da Caparica, Portugal
| | - Luís Jaime Mota
- Research Unit on Applied Molecular Biosciences (UCIBIO) - REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Costa da Caparica, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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32
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Nguyen PH, Lutter EI, Hackstadt T. Chlamydia trachomatis inclusion membrane protein MrcA interacts with the inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) to regulate extrusion formation. PLoS Pathog 2018; 14:e1006911. [PMID: 29543918 PMCID: PMC5854415 DOI: 10.1371/journal.ppat.1006911] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 01/30/2018] [Indexed: 11/25/2022] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that replicates within a vacuole termed an inclusion. At the end of their intracellular developmental cycle, chlamydiae are released either by lysis of the host cell or extrusion of the intact inclusion. The inclusion membrane is extensively modified by the insertion of type III secreted inclusion membrane proteins, Incs, which contribute to inclusion membrane structure and facilitate host-pathogen interactions. An interaction was identified between the inclusion membrane protein, MrcA, and the Ca2+ channel inositol-1,4,5-trisphosphate receptor, type 3 (ITPR3). ITPR3 was recruited and localized to active Src-family-kinase rich microdomains on the inclusion membrane as was the Ca2+ sensor, STIM1. Disruption of MrcA by directed mutagenesis resulted in loss of ITPR3 recruitment and simultaneous reduction of chlamydial release by extrusion. Complementation of MrcA restored ITPR3 recruitment and extrusion. Inhibition of extrusion was also observed following siRNA depletion of host ITPR3 or STIM1. Chlamydial extrusion was also inhibited by the calcium chelator BAPTA-AM. Each of these treatments resulted in a concomitant reduction in phosphorylation of the myosin regulatory light chain (MLC2) and a loss of myosin motor activity at the end of the developmental cycle which is consistent with the reduced extrusion formation. These studies suggest that Ca2+ signaling pathways play an important role in regulation of release mechanisms by C. trachomatis.
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Affiliation(s)
- Phu Hai Nguyen
- Host-Parasite Interactions Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Erika I. Lutter
- Host-Parasite Interactions Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Ted Hackstadt
- Host-Parasite Interactions Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
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33
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Sedzicki J, Tschon T, Low SH, Willemart K, Goldie KN, Letesson JJ, Stahlberg H, Dehio C. 3D correlative electron microscopy reveals continuity of Brucella-containing vacuoles with the endoplasmic reticulum. J Cell Sci 2018; 131:jcs.210799. [PMID: 29361547 DOI: 10.1242/jcs.210799] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 01/04/2018] [Indexed: 01/17/2023] Open
Abstract
Entry of the facultative intracellular pathogen Brucella into host cells results in the formation of endosomal Brucella-containing vacuoles (eBCVs) that initially traffic along the endocytic pathway. eBCV acidification triggers the expression of a type IV secretion system that translocates bacterial effector proteins into host cells. This interferes with lysosomal fusion of eBCVs and supports their maturation to replicative Brucella-containing vacuoles (rBCVs). Bacteria replicate in rBCVs to large numbers, eventually occupying most of the cytoplasmic volume. As rBCV membranes tightly wrap each individual bacterium, they are constantly being expanded and remodeled during exponential bacterial growth. rBCVs are known to carry endoplasmic reticulum (ER) markers; however, the relationship of the vacuole to the genuine ER has remained elusive. Here, we have reconstructed the 3-dimensional ultrastructure of rBCVs and associated ER by correlative structured illumination microscopy (SIM) and focused ion beam/scanning electron microscopic tomography (FIB/SEM). Studying B. abortus-infected HeLa cells and trophoblasts derived from B. melitensis-infected mice, we demonstrate that rBCVs are complex and interconnected compartments that are continuous with neighboring ER cisternae, thus supporting a model that rBCVs are extensions of genuine ER.
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Affiliation(s)
- Jaroslaw Sedzicki
- Focal Area Infection Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland.,Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Therese Tschon
- Focal Area Infection Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Shyan Huey Low
- Focal Area Infection Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Kevin Willemart
- Microorganisms Biology Research Unit (URBM, Unité de Recherche en Biologie des Microorganismes), University of Namur, 5000 Namur, Belgium
| | - Kenneth N Goldie
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Jean-Jacques Letesson
- Microorganisms Biology Research Unit (URBM, Unité de Recherche en Biologie des Microorganismes), University of Namur, 5000 Namur, Belgium
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Christoph Dehio
- Focal Area Infection Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland
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NLR surveillance of essential SEC-9 SNARE proteins induces programmed cell death upon allorecognition in filamentous fungi. Proc Natl Acad Sci U S A 2018; 115:E2292-E2301. [PMID: 29463729 DOI: 10.1073/pnas.1719705115] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In plants and metazoans, intracellular receptors that belong to the NOD-like receptor (NLR) family are major contributors to innate immunity. Filamentous fungal genomes contain large repertoires of genes encoding for proteins with similar architecture to plant and animal NLRs with mostly unknown function. Here, we identify and molecularly characterize patatin-like phospholipase-1 (PLP-1), an NLR-like protein containing an N-terminal patatin-like phospholipase domain, a nucleotide-binding domain (NBD), and a C-terminal tetratricopeptide repeat (TPR) domain. PLP-1 guards the essential SNARE protein SEC-9; genetic differences at plp-1 and sec-9 function to trigger allorecognition and cell death in two distantly related fungal species, Neurospora crassa and Podospora anserina Analyses of Neurospora population samples revealed that plp-1 and sec-9 alleles are highly polymorphic, segregate into discrete haplotypes, and show transspecies polymorphism. Upon fusion between cells bearing incompatible sec-9 and plp-1 alleles, allorecognition and cell death are induced, which are dependent upon physical interaction between SEC-9 and PLP-1. The central NBD and patatin-like phospholipase activity of PLP-1 are essential for allorecognition and cell death, while the TPR domain and the polymorphic SNARE domain of SEC-9 function in conferring allelic specificity. Our data indicate that fungal NLR-like proteins function similar to NLR immune receptors in plants and animals, showing that NLRs are major contributors to innate immunity in plants and animals and for allorecognition in fungi.
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35
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Weber MM, Faris R. Subversion of the Endocytic and Secretory Pathways by Bacterial Effector Proteins. Front Cell Dev Biol 2018; 6:1. [PMID: 29417046 PMCID: PMC5787570 DOI: 10.3389/fcell.2018.00001] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 01/09/2018] [Indexed: 12/22/2022] Open
Abstract
Intracellular bacteria have developed numerous strategies to hijack host vesicular trafficking pathways to form their unique replicative niches. To promote intracellular replication, the bacteria must interact with host organelles and modulate host signaling pathways to acquire nutrients and membrane for the growing parasitophorous vacuole all while suppressing activation of the immune response. To facilitate host cell subversion, bacterial pathogens use specialized secretion systems to deliver bacterial virulence factors, termed effectors, into the host cell that mimic, agonize, and/or antagonize the function of host proteins. In this review we will discuss how bacterial effector proteins from Coxiella burnetii, Brucella abortus, Salmonella enterica serovar Typhimurium, Legionella pneumophila, Chlamydia trachomatis, and Orientia tsutsugamushi manipulate the endocytic and secretory pathways. Understanding how bacterial effector proteins manipulate host processes not only gives us keen insight into bacterial pathogenesis, but also enhances our understanding of how eukaryotic membrane trafficking is regulated.
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Affiliation(s)
- Mary M Weber
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States
| | - Robert Faris
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, United States
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36
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Bhattacharya T, Newton ILG. Mi Casa es Su Casa: how an intracellular symbiont manipulates host biology. Environ Microbiol 2017; 21:10.1111/1462-2920.13964. [PMID: 29076641 PMCID: PMC5924462 DOI: 10.1111/1462-2920.13964] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/16/2017] [Accepted: 10/19/2017] [Indexed: 12/17/2022]
Abstract
Wolbachia pipientis, the most common intracellular infection on the planet, infects 40% of insects as well as nematodes, isopods and arachnids. Wolbachia are obligately intracellular and challenging to study; there are no genetic tools for manipulating Wolbachia nor can they be cultured outside of host cells. Despite these roadblocks, the research community has defined a set of Wolbachia loci involved in host interaction: Wolbachia effectors. Through the use of Drosophila genetics, surrogate systems and biochemistry, the field has begun to define the toolkit Wolbachia use for host manipulation. Below we review recent findings identifying these Wolbachia effectors and point to potential, as yet uncharacterized, links between known phenotypes induced by Wolbachia infection and predicted effectors.
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Affiliation(s)
| | - Irene L G Newton
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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37
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Banhart S, Rose L, Aeberhard L, Koch-Edelmann S, Heuer D. Chlamydia trachomatis and its interaction with the cellular retromer. Int J Med Microbiol 2017; 308:197-205. [PMID: 29122514 DOI: 10.1016/j.ijmm.2017.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/16/2017] [Accepted: 10/24/2017] [Indexed: 11/26/2022] Open
Abstract
Chlamydia trachomatis is an important human pathogen. This obligate intracellular bacterium grows inside the eukaryotic cell in a membrane-bound compartment, the inclusion. Recent global approaches describe the interactions of C. trachomatis with its host cell and indicate the inclusion is an intracellular trafficking hub embedded into the cellular vesicular trafficking pathways recruiting subunits of the retromer protein complex of the host cell. Here we review these recent developments in deciphering Chlamydia-host cell interactions with emphasis on the role of the retromer complex.
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Affiliation(s)
- Sebastian Banhart
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany
| | - Laura Rose
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany
| | - Lukas Aeberhard
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany
| | - Sophia Koch-Edelmann
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany
| | - Dagmar Heuer
- Division "Sexually Transmitted Bacterial Infections" (FG 19), Robert Koch Institute, Berlin, Germany.
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38
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O'Meara CP, Armitage CW, Andrew DW, Kollipara A, Lycke NY, Potter AA, Gerdts V, Petrovsky N, Beagley KW. Multistage vaccines containing outer membrane, type III secretion system and inclusion membrane proteins protects against a Chlamydia genital tract infection and pathology. Vaccine 2017; 35:3883-3888. [PMID: 28602608 DOI: 10.1016/j.vaccine.2017.05.063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/20/2017] [Accepted: 05/23/2017] [Indexed: 01/07/2023]
Abstract
Pathogens with a complex lifecycles can effectively evade host immunity in part due to each developmental stage expressing unique sets of antigens. Multisubunit vaccines incorporating signature antigens reflecting distinct developmental stages (multistage vaccines) have proven effective against viral, bacterial and parasitic infection at preventing pathogen evasion of host immunity. Chlamydia trachomatis is characterized by a biphasic extra/intracellular developmental cycle and an acute/persistent (latent) metabolic state; hence a multistage vaccine may prevent immune evasion and enhance clearance. Here we tested the efficacy of a multistage vaccine containing outer membrane (MOMP and PmpG), type three secretion system (T3SS) (CdsF and TC0873) and inclusion membrane proteins (IncA and TC0500) in mice against an intravaginal challenge with Chlamydia muridarum. Comparison of single (eg. MOMP) and double antigen vaccines (eg. MOMP and PmpG), largely targeting the extracellular stage, elicited significant yet comparable protection against vaginal shedding when compared to unimmunized control mice. Utilization of different adjuvants (ISCOMATRIX - IMX, PCEP/polyI:C/IDR1002 - VIDO, CTA1-DD and ADVAX) and numerous immunization routes (subcutaneous - SQ and intranasal - IN) further enhanced protection against infection. However, a multistage vaccine elicited significantly greater protection against vaginal shedding and upper genital tract pathology than vaccines targeting only extra- or intracellular stages. This indicates that protection elicited by a vaccine targeting extracellular chlamydial antigens could be improved by including chlamydial antigen expressed during intracellular phase.
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Affiliation(s)
- Connor P O'Meara
- Institute of Health and Biomedical Innovation (IHBI) and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia; Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Baden-Wüttemburg, Germany
| | - Charles W Armitage
- Institute of Health and Biomedical Innovation (IHBI) and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Dean W Andrew
- Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Avinash Kollipara
- Institute of Health and Biomedical Innovation (IHBI) and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Nils Y Lycke
- Mucosal Immunobiology and Vaccine Centre, University of Gothenburg, Sweden
| | - Andrew A Potter
- Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, Canada
| | - Volker Gerdts
- Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, Canada
| | - Nikolai Petrovsky
- Vaxine Pty Ltd, Adelaide, Australia; Department of Endocrinology, Flinders Medical Centre/Flinders University, Adelaide, Australia
| | - Kenneth W Beagley
- Institute of Health and Biomedical Innovation (IHBI) and School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
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Paul B, Kim HS, Kerr MC, Huston WM, Teasdale RD, Collins BM. Structural basis for the hijacking of endosomal sorting nexin proteins by Chlamydia trachomatis. eLife 2017; 6. [PMID: 28226239 PMCID: PMC5348129 DOI: 10.7554/elife.22311] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/19/2017] [Indexed: 12/17/2022] Open
Abstract
During infection chlamydial pathogens form an intracellular membrane-bound replicative niche termed the inclusion, which is enriched with bacterial transmembrane proteins called Incs. Incs bind and manipulate host cell proteins to promote inclusion expansion and provide camouflage against innate immune responses. Sorting nexin (SNX) proteins that normally function in endosomal membrane trafficking are a major class of inclusion-associated host proteins, and are recruited by IncE/CT116. Crystal structures of the SNX5 phox-homology (PX) domain in complex with IncE define the precise molecular basis for these interactions. The binding site is unique to SNX5 and related family members SNX6 and SNX32. Intriguingly the site is also conserved in SNX5 homologues throughout evolution, suggesting that IncE captures SNX5-related proteins by mimicking a native host protein interaction. These findings thus provide the first mechanistic insights both into how chlamydial Incs hijack host proteins, and how SNX5-related PX domains function as scaffolds in protein complex assembly.
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Affiliation(s)
- Blessy Paul
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - Hyun Sung Kim
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - Markus C Kerr
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | | | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
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Rucks EA, Olson MG, Jorgenson LM, Srinivasan RR, Ouellette SP. Development of a Proximity Labeling System to Map the Chlamydia trachomatis Inclusion Membrane. Front Cell Infect Microbiol 2017; 7:40. [PMID: 28261569 PMCID: PMC5309262 DOI: 10.3389/fcimb.2017.00040] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 02/03/2017] [Indexed: 11/13/2022] Open
Abstract
Chlamydia grows within a membrane-bound vacuole termed an inclusion. The cellular processes that support the biogenesis and integrity of this pathogen-specified parasitic organelle are not understood. Chlamydia secretes integral membrane proteins called Incs that insert into the chlamydial inclusion membrane (IM). Incs contain at least two hydrophobic transmembrane domains flanked by termini, which vary in size and are exposed to the host cytosol. In addition, Incs are temporally expressed during the chlamydial developmental cycle. Data examining Inc function are limited because of (i) the difficulty in working with hydrophobic proteins and (ii) the inherent fragility of the IM. We hypothesize that Incs function collaboratively to maintain the integrity of the chlamydial inclusion with small Incs organizing the IM and larger Incs interfacing with host cell machinery. To study this hypothesis, we have adapted a proximity-labeling strategy using APEX2, a mutant soybean ascorbate peroxidase that biotinylates interacting and proximal proteins within minutes in the presence of H2O2 and its exogenous substrate, biotin-phenol. We successfully expressed, from an inducible background, APEX2 alone, or fusion proteins of IncATM (TM = transmembrane domain only), IncA, and IncF with APEX2 in Chlamydia trachomatis serovar L2. IncF-APEX2, IncA TM -APEX2, and IncA-APEX2 localized to the IM whereas APEX2, lacking a secretion signal, remained associated with the bacteria. We determined the impact of overexpression on inclusion diameter, plasmid stability, and Golgi-derived sphingomyelin acquisition. While there was an overall impact of inducing construct expression, IncF-APEX2 overexpression most negatively impacted these measurements. Importantly, Inc-APEX2 expression in the presence of biotin-phenol resulted in biotinylation of the IM. These data suggest that Inc expression is regulated to control optimal IM biogenesis. We subsequently defined lysis conditions that solubilized known Incs and were compatible with pulldown conditions. Importantly, we have created powerful tools to allow direct examination of the dynamic composition of the IM, which will provide novel insights into key interactions that promote chlamydial growth and development within the inclusion.
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Affiliation(s)
- Elizabeth A Rucks
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota Vermillion, SD, USA
| | - Macy G Olson
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota Vermillion, SD, USA
| | - Lisa M Jorgenson
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota Vermillion, SD, USA
| | - Rekha R Srinivasan
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota Vermillion, SD, USA
| | - Scot P Ouellette
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota Vermillion, SD, USA
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Cueto JA, Vanrell MC, Salassa BN, Nola S, Galli T, Colombo MI, Romano PS. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors required during Trypanosoma cruzi parasitophorous vacuole development. Cell Microbiol 2017; 19. [PMID: 27992096 DOI: 10.1111/cmi.12713] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 12/02/2016] [Accepted: 12/15/2016] [Indexed: 01/19/2023]
Abstract
Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular parasite that exploits different host vesicular pathways to invade the target cells. Vesicular and target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are key proteins of the intracellular membrane fusion machinery. During the early times of T. cruzi infection, several vesicles are attracted to the parasite contact sites in the plasma membrane. Fusion of these vesicles promotes the formation of the parasitic vacuole and parasite entry. In this work, we study the requirement and the nature of SNAREs involved in the fusion events that take place during T. cruzi infection. Our results show that inhibition of N-ethylmaleimide-sensitive factor protein, a protein required for SNARE complex disassembly, impairs T. cruzi infection. Both TI-VAMP/VAMP7 and cellubrevin/VAMP3, two v-SNAREs of the endocytic and exocytic pathways, are specifically recruited to the parasitophorous vacuole membrane in a synchronized manner but, although VAMP3 is acquired earlier than VAMP7, impairment of VAMP3 by tetanus neurotoxin fails to reduce T. cruzi infection. In contrast, reduction of VAMP7 activity by expression of VAMP7's longin domain, depletion by small interfering RNA or knockout, significantly decreases T. cruzi infection susceptibility as a result of a minor acquisition of lysosomal components to the parasitic vacuole. In addition, overexpression of the VAMP7 partner Vti1b increases the infection, whereas expression of a KIF5 kinesin mutant reduces VAMP7 recruitment to vacuole and, concomitantly, T. cruzi infection. Altogether, these data support a key role of TI-VAMP/VAMP7 in the fusion events that culminate in the T. cruzi parasitophorous vacuole development.
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Affiliation(s)
- Juan Agustín Cueto
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina.,Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Cristina Vanrell
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Betiana Nebaí Salassa
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Sébastien Nola
- Membrane Traffic in Health & Disease, INSERM ERL U950, Univ Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, Paris, France
| | - Thierry Galli
- Membrane Traffic in Health & Disease, INSERM ERL U950, Univ Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, Paris, France
| | - María Isabel Colombo
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Patricia Silvia Romano
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
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42
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Fozo EM, Rucks EA. The Making and Taking of Lipids: The Role of Bacterial Lipid Synthesis and the Harnessing of Host Lipids in Bacterial Pathogenesis. Adv Microb Physiol 2016; 69:51-155. [PMID: 27720012 DOI: 10.1016/bs.ampbs.2016.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In order to survive environmental stressors, including those induced by growth in the human host, bacterial pathogens will adjust their membrane physiology accordingly. These physiological changes also include the use of host-derived lipids to alter their own membranes and feed central metabolic pathways. Within the host, the pathogen is exposed to many stressful stimuli. A resulting adaptation is for pathogens to scavenge the host environment for readily available lipid sources. The pathogen takes advantage of these host-derived lipids to increase or decrease the rigidity of their own membranes, to provide themselves with valuable precursors to feed central metabolic pathways, or to impact host signalling and processes. Within, we review the diverse mechanisms that both extracellular and intracellular pathogens employ to alter their own membranes as well as their use of host-derived lipids in membrane synthesis and modification, in order to increase survival and perpetuate disease within the human host. Furthermore, we discuss how pathogen employed mechanistic utilization of host-derived lipids allows for their persistence, survival and potentiation of disease. A more thorough understanding of all of these mechanisms will have direct consequences for the development of new therapeutics, and specifically, therapeutics that target pathogens, while preserving normal flora.
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Affiliation(s)
- E M Fozo
- University of Tennessee, Knoxville, TN, United States.
| | - E A Rucks
- Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States.
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43
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Radomski N, Einenkel R, Müller A, Knittler MR. Chlamydia-host cell interaction not only from a bird's eye view: some lessons fromChlamydia psittaci. FEBS Lett 2016; 590:3920-3940. [DOI: 10.1002/1873-3468.12295] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 07/06/2016] [Accepted: 07/07/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Nadine Radomski
- Friedrich-Loeffler-Institut; Institute of Immunology; Isle of Riems Germany
| | - Rebekka Einenkel
- Friedrich-Loeffler-Institut; Institute of Immunology; Isle of Riems Germany
| | - Anne Müller
- Friedrich-Loeffler-Institut; Institute of Immunology; Isle of Riems Germany
| | - Michael R Knittler
- Friedrich-Loeffler-Institut; Institute of Immunology; Isle of Riems Germany
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Campodonico EM, Roy CR, Ninio S. Legionella pneumophila Type IV Effectors YlfA and YlfB Are SNARE-Like Proteins that Form Homo- and Heteromeric Complexes and Enhance the Efficiency of Vacuole Remodeling. PLoS One 2016; 11:e0159698. [PMID: 27459495 PMCID: PMC4961411 DOI: 10.1371/journal.pone.0159698] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 06/13/2016] [Indexed: 11/28/2022] Open
Abstract
Legionella pneumophila is a Gram-negative bacterium that can colonize both freshwater protozoa and human alveolar macrophages, the latter infection resulting in Legionnaires’ disease. The intracellular lifecycle of L. pneumophila requires extensive manipulation of its host cell, which is carried out by effector proteins that are translocated into the host cell through the Dot/Icm type IV secretion system. This study focuses on a pair of highly similar type IV substrates called YlfA/LegC7 and YlfB/LegC2 that were initially identified in a screen for proteins that cause growth inhibition in yeast. Analysis of truncation mutants revealed that the hydrophobic residues in the Ylf amino termini were required for localization of each protein to the membranes of host cells. Central and carboxy terminal coiled coil domains were found to mediate binding of YlfA and YlfB to themselves and to each other. In vivo, a ΔylfA ΔylfB double mutant strain of L. pneumophila was shown to be defective in establishing a vacuole that supports bacterial replication. This phenotype was subsequently correlated with a decrease in the association of endoplasmic reticulum (ER)-derived vesicles with vacuoles containing ΔylfA ΔylfB mutant bacteria. These data suggest that the Ylf proteins are membrane-associated effectors that enhance remodeling of the L. pneumophila -containing vacuole by promoting association and possibly fusion of ER-derived membrane vesicles with the bacterial compartment.
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Affiliation(s)
- Eva M. Campodonico
- Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Craig R. Roy
- Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Shira Ninio
- Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America
- The Yigal Allon Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, Migdal, Israel
- * E-mail:
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Direct targeting of membrane fusion by SNARE mimicry: Convergent evolution of Legionella effectors. Proc Natl Acad Sci U S A 2016; 113:8807-12. [PMID: 27436892 DOI: 10.1073/pnas.1608755113] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Legionella pneumophila, the Gram-negative pathogen causing Legionnaires' disease, infects host cells by hijacking endocytic pathways and forming a Legionella-containing vacuole (LCV) in which the bacteria replicate. To promote LCV expansion and prevent lysosomal targeting, effector proteins are translocated into the host cell where they alter membrane traffic. Here we show that three of these effectors [LegC2 (Legionella eukaryotic-like gene C2)/YlfB (yeast lethal factor B), LegC3, and LegC7/YlfA] functionally mimic glutamine (Q)-SNARE proteins. In infected cells, the three proteins selectively form complexes with the endosomal arginine (R)-SNARE vesicle-associated membrane protein 4 (VAMP4). When reconstituted in proteoliposomes, these proteins avidly fuse with liposomes containing VAMP4, resulting in a stable complex with properties resembling canonical SNARE complexes. Intriguingly, however, the LegC/SNARE hybrid complex cannot be disassembled by N-ethylmaleimide-sensitive factor. We conclude that LegCs use SNARE mimicry to divert VAMP4-containing vesicles for fusion with the LCV, thus promoting its expansion. In addition, the LegC/VAMP4 complex avoids the host's disassembly machinery, thus effectively trapping VAMP4 in an inactive state.
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46
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Di Russo Case E, Smith JA, Ficht TA, Samuel JE, de Figueiredo P. Space: A Final Frontier for Vacuolar Pathogens. Traffic 2016; 17:461-74. [PMID: 26842840 PMCID: PMC6048968 DOI: 10.1111/tra.12382] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/29/2016] [Accepted: 01/29/2016] [Indexed: 12/12/2022]
Abstract
There is a fundamental gap in our understanding of how a eukaryotic cell apportions the limited space within its cell membrane. Upon infection, a cell competes with intracellular pathogens for control of this same precious resource. The struggle between pathogen and host provides us with an opportunity to uncover the mechanisms regulating subcellular space by understanding how pathogens modulate vesicular traffic and membrane fusion events to create a specialized compartment for replication. By comparing several important intracellular pathogens, we review the molecular mechanisms and trafficking pathways that drive two space allocation strategies, the formation of tight and spacious pathogen-containing vacuoles. Additionally, we discuss the potential advantages of each pathogenic lifestyle, the broader implications these lifestyles might have for cellular biology and outline exciting opportunities for future investigation.
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Affiliation(s)
- Elizabeth Di Russo Case
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX, USA
| | - Judith A. Smith
- Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Thomas A. Ficht
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA
| | - James E. Samuel
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX, USA
| | - Paul de Figueiredo
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX, USA
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA
- Norman Borlaug Center, Texas A&M University, College Station, TX, USA
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A Functional Core of IncA Is Required for Chlamydia trachomatis Inclusion Fusion. J Bacteriol 2016; 198:1347-55. [PMID: 26883826 DOI: 10.1128/jb.00933-15] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 02/10/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Chlamydia trachomatis is an obligate intracellular pathogen that is the etiological agent of a variety of human diseases, including blinding trachoma and sexually transmitted infections. Chlamydiae replicate within a membrane-bound compartment, termed an inclusion, which they extensively modify by the insertion of type III secreted proteins called Inc proteins. IncA is an inclusion membrane protein that encodes two coiled-coil domains that are homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) motifs. Recent biochemical evidence suggests that a functional core, composed of SNARE-like domain 1 (SLD-1) and part of SNARE-like domain 2 (SLD-2), is required for the characteristic homotypic fusion of C. trachomatis inclusions in multiply infected cells. To verify the importance of IncA in homotypic fusion in Chlamydia, we generated an incA::bla mutant. Insertional inactivation of incA resulted in the formation of nonfusogenic inclusions, a phenotype that was completely rescued by complementation with full-length IncA. Rescue of homotypic inclusion fusion was dependent on the presence of the functional core consisting of SLD-1 and part of SLD-2. Collectively, these results confirm in vitro membrane fusion assays identifying functional domains of IncA and expand the genetic tools available for identification of chlamydia with a method for complementation of site-specific mutants. IMPORTANCE Chlamydia trachomatis replicates within a parasitophorous vacuole termed an inclusion. The chlamydial inclusions are nonfusogenic with vesicles in the endocytic pathway but, in multiply infected cells, fuse with each other to form a single large inclusion. This homotypic fusion is dependent upon the presence of a chlamydial inclusion membrane-localized protein, IncA. Specificity of membrane fusion in eukaryotic cells is regulated by SNARE (soluble N-ethylmaleimide sensitive factor attachment receptor) proteins on the cytosolic face of vesicles and target membranes. IncA contains two SNARE-like domains. Newly developed genetic tools for the complementation of targeted mutants in C. trachomatis are used to confirm the minimal requirement of SNARE-like motifs necessary to promote the homotypic fusion of inclusions.
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48
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Personnic N, Bärlocher K, Finsel I, Hilbi H. Subversion of Retrograde Trafficking by Translocated Pathogen Effectors. Trends Microbiol 2016; 24:450-462. [PMID: 26924068 DOI: 10.1016/j.tim.2016.02.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 01/22/2016] [Accepted: 02/01/2016] [Indexed: 12/22/2022]
Abstract
Intracellular bacterial pathogens subvert the endocytic bactericidal pathway to form specific replication-permissive compartments termed pathogen vacuoles or inclusions. To this end, the pathogens employ type III or type IV secretion systems, which translocate dozens, if not hundreds, of different effector proteins into their host cells, where they manipulate vesicle trafficking and signaling pathways in favor of the intruders. While the distinct cocktail of effectors defines the specific processes by which a pathogen vacuole is formed, the different pathogens commonly target certain vesicle trafficking routes, including the endocytic or secretory pathway. Recently, the retrograde transport pathway from endosomal compartments to the trans-Golgi network emerged as an important route affecting pathogen vacuole formation. Here, we review current insight into the host cell's retrograde trafficking pathway and how vacuolar pathogens of the genera Legionella, Coxiella, Salmonella, Chlamydia, and Simkania employ mechanistically distinct strategies to subvert this pathway, thus promoting intracellular survival and replication.
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Affiliation(s)
- Nicolas Personnic
- Institute of Medical Microbiology, Department of Medicine, University of Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland
| | - Kevin Bärlocher
- Institute of Medical Microbiology, Department of Medicine, University of Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland
| | - Ivo Finsel
- Max von Pettenkofer Institute, Ludwig-Maximilians University Munich, Pettenkoferstrasse 9a, 80336 Munich, Germany
| | - Hubert Hilbi
- Institute of Medical Microbiology, Department of Medicine, University of Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland; Max von Pettenkofer Institute, Ludwig-Maximilians University Munich, Pettenkoferstrasse 9a, 80336 Munich, Germany.
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Membrane contact sites between pathogen-containing compartments and host organelles. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:895-899. [PMID: 26825687 DOI: 10.1016/j.bbalip.2016.01.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/20/2016] [Accepted: 01/25/2016] [Indexed: 11/23/2022]
Abstract
Intracellular pathogens survive and replicate within specialised membrane-bound compartments that can be considered as pseudo-organelles. Using the obligate intracellular bacterium Chlamydia as an illustrative example, we consider the modes of lipid transport between pathogen-containing compartments and host organelles, including the formation of static membrane contact sites. We discuss how lipid scavenging can be mediated via the reprogramming of cellular transporters at these interfaces and describe recent data suggesting that pathogen effectors modulate the formation of specific membrane contacts. Further study of these emerging mechanisms is likely to yield new insights into the cell biology of lipid transport and organelle communication, which highlights potential new targets and strategies for future therapeutics. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
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50
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Nogueira AT, Pedrosa AT, Carabeo RA. Manipulation of the Host Cell Cytoskeleton by Chlamydia. Curr Top Microbiol Immunol 2016; 412:59-80. [PMID: 27197645 DOI: 10.1007/82_2016_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Chlamydiae are obligate intracellular pathogens. They undergo a biphasic developmental cycle differentiating between the infectious but metabolically quiescent elementary body and the vegetative, but non-infectious reticulate body. Chlamydia spends a significant portion of its development in the non-infectious stage, demanding an effective strategy of manipulating the host cells to ensure its intracellular survival and replication. A common target of all Chlamydia species studied so far is the host cell cytoskeleton, with past and recent findings revealing crucial roles in invasion, inclusion maintenance, nutrient acquisition, and egress. The molecular details of how Chlamydia co-opts the cytoskeleton is becoming clearer, with bacterial factors and their corresponding host cell targets identified.
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Affiliation(s)
- Ana T Nogueira
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Antonio T Pedrosa
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Rey A Carabeo
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA.
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