1
|
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.
Collapse
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
| |
Collapse
|
2
|
Fisher DJ, Beare PA. Recent advances in genetic systems in obligate intracellular human-pathogenic bacteria. Front Cell Infect Microbiol 2023; 13:1202245. [PMID: 37404720 PMCID: PMC10315504 DOI: 10.3389/fcimb.2023.1202245] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 05/22/2023] [Indexed: 07/06/2023] Open
Abstract
The ability to genetically manipulate a pathogen is fundamental to discovering factors governing host-pathogen interactions at the molecular level and is critical for devising treatment and prevention strategies. While the genetic "toolbox" for many important bacterial pathogens is extensive, approaches for modifying obligate intracellular bacterial pathogens were classically limited due in part to the uniqueness of their obligatory lifestyles. Many researchers have confronted these challenges over the past two and a half decades leading to the development of multiple approaches to construct plasmid-bearing recombinant strains and chromosomal gene inactivation and deletion mutants, along with gene-silencing methods enabling the study of essential genes. This review will highlight seminal genetic achievements and recent developments (past 5 years) for Anaplasma spp., Rickettsia spp., Chlamydia spp., and Coxiella burnetii including progress being made for the still intractable Orientia tsutsugamushi. Alongside commentary of the strengths and weaknesses of the various approaches, future research directions will be discussed to include methods for C. burnetii that should have utility in the other obligate intracellular bacteria. Collectively, the future appears bright for unraveling the molecular pathogenic mechanisms of these significant pathogens.
Collapse
Affiliation(s)
- Derek J. Fisher
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, United States
| | - Paul A. Beare
- Rocky Mountain Laboratory, National Institute of Health, Hamilton, MT, United States
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Garvin L, Vande Voorde R, Dickinson M, Carrell S, Hybiske K, Rockey D. A broad-spectrum cloning vector that exists as both an integrated element and a free plasmid in Chlamydia trachomatis. PLoS One 2021; 16:e0261088. [PMID: 34914750 PMCID: PMC8675754 DOI: 10.1371/journal.pone.0261088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/23/2021] [Indexed: 12/23/2022] Open
Abstract
Plasmid transformation of chlamydiae has created new opportunities to investigate host-microbe interactions during chlamydial infections; however, there are still limitations. Plasmid transformation requires a replicon derived from the native Chlamydia plasmid, and these transformations are species-specific. We explored the utility of a broad host-range plasmid, pBBR1MCS-4, to transform chlamydiae, with a goal of simplifying the transformation process. The plasmid was modified to contain chromosomal DNA from C. trachomatis to facilitate homologous recombination. Sequences flanking incA were cloned into the pBBR1MCS-4 vector along with the GFP:CAT cassette from the pSW2-GFP chlamydial shuttle vector. The final plasmid construct, pBVR2, was successfully transformed into C. trachomatis strain L2-434. Chlamydial transformants were analyzed by immunofluorescence microscopy and positive clones were sequentially purified using limiting dilution. PCR and PacBio-based whole genome sequencing were used to determine if the plasmid was maintained within the chromosome or as an episome. PacBio sequencing of the cloned transformants revealed allelic exchange events between the chromosome and plasmid pBVR2 that replaced chromosomal incA with the plasmid GFP:CAT cassette. The data also showed evidence of full integration of the plasmid into the bacterial chromosome. While some plasmids were fully integrated, some were maintained as episomes and could be purified and retransformed into E. coli. Thus, the plasmid can be successfully transformed into chlamydia without a chlamydial origin of replication and can exist in multiple states within a transformed population.
Collapse
Affiliation(s)
- Lotisha Garvin
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
| | - Rebecca Vande Voorde
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
| | - Mary Dickinson
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Disease (CERID), University of Washington, Seattle, WA, United States of America
| | - Steven Carrell
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
| | - Kevin Hybiske
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Disease (CERID), University of Washington, Seattle, WA, United States of America
| | - Daniel Rockey
- Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
- * E-mail:
| |
Collapse
|
5
|
Gulyuk AV, LaJeunesse DR, Collazo R, Ivanisevic A. Tuning Microbial Activity via Programmatic Alteration of Cell/Substrate Interfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2004655. [PMID: 34028885 PMCID: PMC10167751 DOI: 10.1002/adma.202004655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 11/11/2020] [Indexed: 05/11/2023]
Abstract
A wide portfolio of advanced programmable materials and structures has been developed for biological applications in the last two decades. Particularly, due to their unique properties, semiconducting materials have been utilized in areas of biocomputing, implantable electronics, and healthcare. As a new concept of such programmable material design, biointerfaces based on inorganic semiconducting materials as substrates introduce unconventional paths for bioinformatics and biosensing. In particular, understanding how the properties of a substrate can alter microbial biofilm behavior enables researchers to better characterize and thus create programmable biointerfaces with necessary characteristics on demand. Herein, the current status of advanced microorganism-inorganic biointerfaces is summarized along with types of responses that can be observed in such hybrid systems. This work identifies promising inorganic material types along with target microorganisms that will be critical for future research on programmable biointerfacial structures.
Collapse
Affiliation(s)
- Alexey V Gulyuk
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Dennis R LaJeunesse
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina-Greensboro, Greensboro, NC, 27401, USA
| | - Ramon Collazo
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Albena Ivanisevic
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| |
Collapse
|
6
|
Banerjee A, Nelson DE. The growing repertoire of genetic tools for dissecting chlamydial pathogenesis. Pathog Dis 2021; 79:ftab025. [PMID: 33930127 PMCID: PMC8112481 DOI: 10.1093/femspd/ftab025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/28/2021] [Indexed: 01/29/2023] Open
Abstract
Multiple species of obligate intracellular bacteria in the genus Chlamydia are important veterinary and/or human pathogens. These pathogens all share similar biphasic developmental cycles and transition between intracellular vegetative reticulate bodies and infectious elementary forms, but vary substantially in their host preferences and pathogenic potential. A lack of tools for genetic engineering of these organisms has long been an impediment to the study of their biology and pathogenesis. However, the refinement of approaches developed in C. trachomatis over the last 10 years, and adaptation of some of these approaches to other Chlamydia spp. in just the last few years, has opened exciting new possibilities for studying this ubiquitous group of important pathogens.
Collapse
Affiliation(s)
- Arkaprabha Banerjee
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - David E Nelson
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| |
Collapse
|
7
|
Favaroni A, Trinks A, Weber M, Hegemann JH, Schnee C. Pmp Repertoires Influence the Different Infectious Potential of Avian and Mammalian Chlamydia psittaci Strains. Front Microbiol 2021; 12:656209. [PMID: 33854490 PMCID: PMC8039305 DOI: 10.3389/fmicb.2021.656209] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/09/2021] [Indexed: 12/21/2022] Open
Abstract
Chlamydia psittaci is the etiological agent of chlamydiosis in birds and can be transmitted to humans, causing severe systemic disease. C. psittaci infects a broad range of hosts; strains are isolated not only from birds but also from mammals, where they seem to have a reduced infectious and zoonotic potential. Comparative analysis of chlamydial genomes revealed the coding sequences of polymorphic membrane proteins (Pmps) to be highly variable regions. Pmps are characterized as adhesins in C. trachomatis and C. pneumoniae and are immunoreactive proteins in several Chlamydia species. Thus, Pmps are considered to be associated with tissue tropism and pathogenicity. C. psittaci harbors 21 Pmps. We hypothesize that the different infectious potential and host tropism of avian and mammalian C. psittaci strains is dependent on differences in their Pmp repertoires. In this study, we experimentally confirmed the different virulence of avian and mammalian strains, by testing the survival rate of infected embryonated eggs and chlamydiae dissemination in the embryos. Further, we investigated the possible involvement of Pmps in host tropism. Analysis of pmp sequences from 10 C. psittaci strains confirmed a high degree of variation, but no correlation with host tropism was identified. However, comparison of Pmp expression profiles from different strains showed that Pmps of the G group are the most variably expressed, also among avian and mammalian strains. To investigate their functions, selected Pmps were recombinantly produced from one avian and one mammalian representative strain and their adhesion abilities and relevance for the infection of C. psittaci strains in avian and mammalian cells were tested. For the first time, we identified Pmp22D, Pmp8G, and OmcB as relevant adhesins, essential during infection of C. psittaci strains in general. Moreover, we propose Pmp17G as a possible key player for host adaptation, as it could only bind to and influence the infection in avian cells, but it had no relevant impact towards infection in mammalian cells. These data support the hypothesis that distinct Pmp repertoires in combination with specific host factors may contribute to host tropism of C. psittaci strains.
Collapse
Affiliation(s)
- Alison Favaroni
- Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut, Jena, Germany
| | - Alexander Trinks
- Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut, Jena, Germany
| | - Michael Weber
- Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut, Jena, Germany
| | - Johannes H Hegemann
- Institute of Functional Microbial Genomics, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - Christiane Schnee
- Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut, Jena, Germany
| |
Collapse
|
8
|
Hanford HE, Von Dwingelo J, Abu Kwaik Y. Bacterial nucleomodulins: A coevolutionary adaptation to the eukaryotic command center. PLoS Pathog 2021; 17:e1009184. [PMID: 33476322 PMCID: PMC7819608 DOI: 10.1371/journal.ppat.1009184] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Through long-term interactions with their hosts, bacterial pathogens have evolved unique arsenals of effector proteins that interact with specific host targets and reprogram the host cell into a permissive niche for pathogen proliferation. The targeting of effector proteins into the host cell nucleus for modulation of nuclear processes is an emerging theme among bacterial pathogens. These unique pathogen effector proteins have been termed in recent years as "nucleomodulins." The first nucleomodulins were discovered in the phytopathogens Agrobacterium and Xanthomonas, where their nucleomodulins functioned as eukaryotic transcription factors or integrated themselves into host cell DNA to promote tumor induction, respectively. Numerous nucleomodulins were recently identified in mammalian pathogens. Bacterial nucleomodulins are an emerging family of pathogen effector proteins that evolved to target specific components of the host cell command center through various mechanisms. These mechanisms include: chromatin dynamics, histone modification, DNA methylation, RNA splicing, DNA replication, cell cycle, and cell signaling pathways. Nucleomodulins may induce short- or long-term epigenetic modifications of the host cell. In this extensive review, we discuss the current knowledge of nucleomodulins from plant and mammalian pathogens. While many nucleomodulins are already identified, continued research is instrumental in understanding their mechanisms of action and the role they play during the progression of pathogenesis. The continued study of nucleomodulins will enhance our knowledge of their effects on nuclear chromatin dynamics, protein homeostasis, transcriptional landscapes, and the overall host cell epigenome.
Collapse
Affiliation(s)
- Hannah E. Hanford
- Department of Microbiology and Immunology, University of Louisville, Kentucky, United States of America
| | - Juanita Von Dwingelo
- Department of Microbiology and Immunology, University of Louisville, Kentucky, United States of America
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Kentucky, United States of America
- Center for Predicative Medicine, College of Medicine, University of Louisville, Kentucky, United States of America
| |
Collapse
|
9
|
Schott BH, Antonia AL, Wang L, Pittman KJ, Sixt BS, Barnes AB, Valdivia RH, Ko DC. Modeling of variables in cellular infection reveals CXCL10 levels are regulated by human genetic variation and the Chlamydia-encoded CPAF protease. Sci Rep 2020; 10:18269. [PMID: 33106516 PMCID: PMC7588472 DOI: 10.1038/s41598-020-75129-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 10/12/2020] [Indexed: 01/01/2023] Open
Abstract
Susceptibility to infectious diseases is determined by a complex interaction between host and pathogen. For infections with the obligate intracellular bacterium Chlamydia trachomatis, variation in immune activation and disease presentation are regulated by both host genetic diversity and pathogen immune evasion. Previously, we discovered a single nucleotide polymorphism (rs2869462) associated with absolute abundance of CXCL10, a pro-inflammatory T-cell chemokine. Here, we report that levels of CXCL10 change during C. trachomatis infection of cultured cells in a manner dependent on both host and pathogen. Linear modeling of cellular traits associated with CXCL10 levels identified a strong, negative correlation with bacterial burden, suggesting that C. trachomatis actively suppresses CXCL10. We identified the pathogen-encoded factor responsible for this suppression as the chlamydial protease- or proteasome-like activity factor, CPAF. Further, we applied our modeling approach to other host cytokines in response to C. trachomatis and found evidence that RANTES, another T-cell chemoattractant, is actively suppressed by Chlamydia. However, this observed suppression of RANTES is not mediated by CPAF. Overall, our results demonstrate that CPAF suppresses CXCL10 to evade the host cytokine response and that modeling of cellular infection parameters can reveal previously unrecognized facets of host-pathogen interactions.
Collapse
Affiliation(s)
- Benjamin H Schott
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, 0049 CARL Building Box 3053, 213 Research Drive, Durham, NC, 27710, USA
- Duke University Program in Genetics and Genomics, Duke University, Durham, NC, 27710, USA
| | - Alejandro L Antonia
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, 0049 CARL Building Box 3053, 213 Research Drive, Durham, NC, 27710, USA
| | - Liuyang Wang
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, 0049 CARL Building Box 3053, 213 Research Drive, Durham, NC, 27710, USA
| | - Kelly J Pittman
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, 0049 CARL Building Box 3053, 213 Research Drive, Durham, NC, 27710, USA
| | - Barbara S Sixt
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, 0049 CARL Building Box 3053, 213 Research Drive, Durham, NC, 27710, USA
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research, Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Alyson B Barnes
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, 0049 CARL Building Box 3053, 213 Research Drive, Durham, NC, 27710, USA
| | - Raphael H Valdivia
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, 0049 CARL Building Box 3053, 213 Research Drive, Durham, NC, 27710, USA
| | - Dennis C Ko
- Department of Molecular Genetics and Microbiology, School of Medicine, Duke University, 0049 CARL Building Box 3053, 213 Research Drive, Durham, NC, 27710, USA.
- Duke University Program in Genetics and Genomics, Duke University, Durham, NC, 27710, USA.
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Duke University, Durham, NC, 27710, USA.
| |
Collapse
|
10
|
Marschall MT, Simnacher U, Walther P, Essig A, Hagemann JB. The Putative Type III Secreted Chlamydia abortus Virulence-Associated Protein CAB063 Targets Lamin and Induces Apoptosis. Front Microbiol 2020; 11:1059. [PMID: 32523581 PMCID: PMC7261910 DOI: 10.3389/fmicb.2020.01059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/29/2020] [Indexed: 01/15/2023] Open
Abstract
Since intracellular survival of all chlamydiae depends on the manipulation of the host cell through type III secreted effector proteins, their characterization is crucial for the understanding of chlamydial pathogenesis. We functionally characterized the putative type III secreted Chlamydia abortus protein CAB063, describe its intracellular localization and identified pro- and eukaryotic binding partners. Based on an experimental infection model and plasmid transfections, we investigated the subcellular localization of CAB063 by immunofluorescence microscopy, immunoelectron microscopy, and Western blot analysis. Pro- and eukaryotic targets were identified by co-immunofluorescence, co-immunoprecipitation, and mass spectrometry. Transmission electron microscopy and flow cytometry were used for morphological and functional investigations on host cell apoptosis. CAB063 localized in the nuclear membrane of the host cell nucleus and we identified the chaperone HSP70 and lamin A/C as pro- and eukaryotic targets, respectively. CAB063-dependent morphological alterations of the host cell nucleus correlated with increased apoptosis rates of infected and CAB063-transfected cells. We provide evidence that CAB063 is a chaperone-folded type III secreted C. abortus virulence factor that targets lamin thereby altering the host cell nuclear membrane structure. This process may be responsible for an increased apoptosis rate at the end of the chlamydial developmental cycle, at which CAB063 is physiologically expressed.
Collapse
Affiliation(s)
| | - Ulrike Simnacher
- Institute of Medical Microbiology and Hygiene, Ulm University Hospital, Ulm, Germany
| | - Paul Walther
- Central Facility for Electron Microscopy, Ulm University, Ulm, Germany
| | - Andreas Essig
- Institute of Medical Microbiology and Hygiene, Ulm University Hospital, Ulm, Germany
| | | |
Collapse
|