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Walker FC, Derré I. Contributions of diverse models of the female reproductive tract to the study of Chlamydia trachomatis-host interactions. Curr Opin Microbiol 2024; 77:102416. [PMID: 38103413 PMCID: PMC10922760 DOI: 10.1016/j.mib.2023.102416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/19/2023]
Abstract
Chlamydia trachomatis is a common cause of sexually transmitted infections in humans with devastating sequelae. Understanding of disease on all scales, from molecular details to the immunology underlying pathology, is essential for identifying new ways of preventing and treating chlamydia. Infection models of various complexity are essential to understand all aspects of chlamydia pathogenesis. Cell culture systems allow for research into molecular details of infection, including characterization of the unique biphasic Chlamydia developmental cycle and the role of type-III-secreted effectors in modifying the host environment to allow for infection. Multicell type and organoid culture provide means to investigate how cells other than the infected cells contribute to the control of infection. Emerging comprehensive three-dimensional biomimetic systems may fill an important gap in current models to provide information on complex phenotypes that cannot be modeled in simpler in vitro models.
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Affiliation(s)
- Forrest C Walker
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, United States of America
| | - Isabelle Derré
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, United States of America.
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2
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Zhang S, Funahashi Y, Tanaka S, Okubo T, Thapa J, Nakamura S, Higashi H, Yamaguchi H. Chlamydia trachomatis relies on the scavenger role of aryl hydrocarbon receptor with detyrosinated tubulin for its intracellular growth, but this is impaired by excess indole. Microbes Infect 2023; 25:105097. [PMID: 36608767 DOI: 10.1016/j.micinf.2022.105097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/29/2022] [Accepted: 12/29/2022] [Indexed: 01/05/2023]
Abstract
Although IFN-γ depletes tryptophan (Trp) as a defense against intracellular Chlamydia trachomatis (Ct) infected to hypoxic vagina, the presence of indole, a precursor of Trp, enables Ct to infect IFN-γ-exposed culture cells. Meanwhile, Trp-derived indole derivatives interact the aryl hydrocarbon receptor (AhR), which is a ligand-dependent transcription factor involved in the cellular homeostasis with tubulin dynamics. Here, the amounts of IFN-γ and indole in cervical swabs with known Ct infection status were measured, and Ct growth in the presence of indole was determined from the perspective of the AhR axis under hypoxia. A positive correlation between the amounts of IFN-γ and indole was found, and both of these amounts were lower in Ct-positive swabs than in Ct-negative ones. Indole as well as other AhR ligands inhibited Ct growth, especially under normoxia. Ct prompted the expression of detyrosinated tubulin (dTTub), but indole inhibited it. Indole did not stimulate the translocation of AhR to nucleus, and it blocked AhR activation in AhR-reporter cells. Ct growth was reduced more effectively under normoxia in AhR-knockdown cells, an effect that was enhanced by indole, which in turn diminished dTTub. Thus, Ct growth relies on the scavenger role of cytosolic AhR responsible for promoting dTTub expression.
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Affiliation(s)
- Saicheng Zhang
- Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, North-12, West-5, Kita-ku, Sapporo 060-0812, Japan.
| | - Yuki Funahashi
- Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, North-12, West-5, Kita-ku, Sapporo 060-0812, Japan.
| | - Satoho Tanaka
- Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, North-12, West-5, Kita-ku, Sapporo 060-0812, Japan.
| | - Torahiko Okubo
- Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, North-12, West-5, Kita-ku, Sapporo 060-0812, Japan.
| | - Jeewan Thapa
- Division of Bioresources, International Institute for Zoonosis Control, Hokkaido University, North-20, West-10, Kita-ku, Sapporo 001-0020, Japan.
| | - Shinji Nakamura
- Division of Biomedical Imaging Research, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan; Division of Ultrastructural Research, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
| | - Hideaki Higashi
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, North-20, West-10, Kita-ku, Sapporo 001-0020, Japan.
| | - Hiroyuki Yamaguchi
- Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, North-12, West-5, Kita-ku, Sapporo 060-0812, Japan.
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Rea V, Bell I, Ball T, Van Raay T. Gut-derived metabolites influence neurodevelopmental gene expression and Wnt signaling events in a germ-free zebrafish model. Microbiome 2022; 10:132. [PMID: 35996200 PMCID: PMC9396910 DOI: 10.1186/s40168-022-01302-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Small molecule metabolites produced by the microbiome are known to be neuroactive and are capable of directly impacting the brain and central nervous system, yet there is little data on the contribution of these metabolites to the earliest stages of neural development and neural gene expression. Here, we explore the impact of deriving zebrafish embryos in the absence of microbes on early neural development as well as investigate whether any potential changes can be rescued with treatment of metabolites derived from the zebrafish gut microbiota. RESULTS Overall, we did not observe any gross morphological changes between treatments but did observe a significant decrease in neural gene expression in embryos raised germ-free, which was rescued with the addition of zebrafish metabolites. Specifically, we identified 354 genes significantly downregulated in germ-free embryos compared to conventionally raised embryos via RNA-Seq analysis. Of these, 42 were rescued with a single treatment of zebrafish gut-derived metabolites to germ-free embryos. Gene ontology analysis revealed that these genes are involved in prominent neurodevelopmental pathways including transcriptional regulation and Wnt signaling. Consistent with the ontology analysis, we found alterations in the development of Wnt dependent events which was rescued in the germ-free embryos treated with metabolites. CONCLUSIONS These findings demonstrate that gut-derived metabolites are in part responsible for regulating critical signaling pathways in the brain, especially during neural development. Video abstract.
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Affiliation(s)
- Victoria Rea
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Ian Bell
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Taylor Ball
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Terence Van Raay
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada.
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Wen Y, Luo F, Zhao L, Su S, Lei W, Liu Y, Shi K, Li Z. Long Non-Coding RNA FGD5-AS1 Induced by Chlamydia trachomatis Infection Inhibits Apoptosis via Wnt/β-Catenin Signaling Pathway. Front Cell Infect Microbiol 2021; 11:701352. [PMID: 34568091 PMCID: PMC8460124 DOI: 10.3389/fcimb.2021.701352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 07/15/2021] [Indexed: 12/12/2022] Open
Abstract
Background Chlamydia trachomatis (Ct) is one of the most common bacterial sexually transmitted infection (STI) pathogens in the world, but the exact pathogenic mechanism still needs to be further elucidated. Long non-coding RNAs (lncRNAs) have become vital regulators in many biological processes. Their role in the interaction between Ct and host cells has not been reported. Methods Microarrays were used to study the expression profiles of lncRNAs and mRNAs in HeLa cells at 12, 24, and 40 h post-infection (hpi). Differentially expressed lncRNAs and mRNAs were verified by RT-qPCR. Coding-non-coding (CNC) network analysis showed co-expression molecules of selected lncRNA. Western blot, flow cytometry, and indirect immunofluorescence were used to detect the effect of lncRNA FGD5-AS1 on apoptosis during Ct infection. Results Compared with the uninfected group, the number of differential lncRNAs were 2,130, 1,081, and 1,101 at 12, 24, and 40 hpi, and the number of differential mRNAs was 1,998, 1,129, and 1,330, respectively. Ct induced differential expression of large amounts of lncRNAs and mRNAs in HeLa cells, indicating that lncRNAs may play roles in the pathogenesis of Ct. RT-qPCR verified six differential lncRNAs and six differential mRNAs, confirming the reliability of the microarray. Among these molecules, lncRNA FGD5-AS1 was found to be upregulated at 12 and 24 hpi. Coding-non-coding (CNC) network analysis showed that co-expressed differential molecules of FGD5-AS1 at 12 and 24 hpi were enriched in the DNA replication and Wnt signaling pathway. The downregulation of FGD5-AS1 decreased the expression of β-catenin and inhibited the translocation of β-catenin and the DNA replication, while it promoted apoptosis of the host cells. Conclusions DNA replication and apoptosis of host cells were affected by upregulating FGD5-AS1 via Wnt/β-catenin pathway during Ct infection. This study provides evidence that lncRNAs are involved in the coaction between Ct and hosts, and provides new insights into the study of lncRNAs that regulate chlamydial infection.
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Affiliation(s)
- Yating Wen
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Fangzhen Luo
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Lanhua Zhao
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Shengmei Su
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Wenbo Lei
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Yi Liu
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Keliang Shi
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Zhongyu Li
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
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Rogan MR, Patterson LL, Byerly CD, Luo T, Paessler S, Veljkovic V, Quade B, McBride JW. Ehrlichia chaffeensis TRP120 Is a Wnt Ligand Mimetic That Interacts with Wnt Receptors and Contains a Novel Repetitive Short Linear Motif That Activates Wnt Signaling. mSphere 2021; 6:6/2/e00216-21. [PMID: 33883266 PMCID: PMC8546699 DOI: 10.1128/msphere.00216-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ehrlichia chaffeensis expresses the TRP120 multifunctional effector, which is known to play a role in phagocytic entry, on the surface of infectious dense-cored ehrlichiae, but a cognate host receptor has not been identified. We recently reported that E. chaffeensis activates canonical Wnt signaling in monocytes to promote bacterial uptake and intracellular survival and that TRP120 was involved in this activation event. To identify the specific mechanism of pathway activation, we hypothesized that TRP120 is a Wnt signaling ligand mimetic that initiates Wnt pathway activity through direct interaction with the Wnt pathway Frizzled family of receptors. In this study, we used confocal immunofluorescence microscopy to demonstrate very strong colocalization between E. chaffeensis and Fzd2, 4, 5, 7, and 9 as well as coreceptor LRP5 at 1 to 3 h postinfection. Direct binding between TRP120 and multiple Fzd receptors was further confirmed by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR). Interfering RNA knockdown of Wnt receptors, coreceptors, and signaling pathway components significantly reduced E. chaffeensis infection, demonstrating that complex and redundant interactions are involved in Wnt pathway exploitation. We utilized in silico approaches to identify a repetitive short linear motif (SLiM) in TRP120 that is homologous to Wnt ligands and used mutant SLiM peptides and an α-TRP120-Wnt-SLiM antibody to demonstrate that the TRP120 Wnt SLiM activates the canonical Wnt pathway and promotes E. chaffeensis infection. This study reports the first example of bacterial mimicry of Wnt pathway ligands and highlights a pathogenic mechanism with potential for targeting by antimicrobial therapeutics.IMPORTANCE Upon infecting mammalian hosts, Ehrlichia chaffeensis establishes a replicative niche in microbe-eating immune system cells where it expertly orchestrates infection and spread. One of the ways Ehrlichia survives within these phagocytes is by activating evolutionarily conserved signaling pathways including the Wnt pathway; however, the molecular details of pathway hijacking have not been defined. This study is significant because it identifies an ehrlichial protein that directly interacts with components of the Wnt receptor complex, influencing pathway activity and promoting infection. Consequentially, Ehrlichia serves as a unique tool to investigate the intricacies of how pathogens repurpose human immune cell signaling and provides an opportunity to better understand many cellular processes in health and disease. Furthermore, understanding how this bacterium utilizes its small genome to survive within cells that evolved to destroy pathogens will facilitate the development of antibacterial therapeutics that could target Ehrlichia as well as other intracellular agents of human disease.
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Affiliation(s)
- Madison R Rogan
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - LaNisha L Patterson
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Caitlan D Byerly
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Tian Luo
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Slobodan Paessler
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
- BiomedProtection, LLC, Galveston, Texas, USA
| | | | - Bethany Quade
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jere W McBride
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, Texas, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
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Dolat L, Valdivia RH. An endometrial organoid model of interactions between Chlamydia and epithelial and immune cells. J Cell Sci 2021; 134:jcs.252403. [PMID: 33468625 DOI: 10.1242/jcs.252403] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
Our understanding of how the obligate intracellular bacterial pathogen Chlamydia trachomatis reprograms the function of infected cells in the upper genital tract is largely based on observations made in cell culture with transformed epithelial cell lines. Here, we describe a primary organoid system derived from endometrial tissue to recapitulate epithelial cell diversity, polarity and ensuing responses to Chlamydia infection. Using high-resolution and time-lapse microscopy, we catalog the infection process in organoids from invasion to egress, including the reorganization of the cytoskeleton and positioning of intracellular organelles. We show this model is amenable to screening C. trachomatis mutants for defects in the fusion of pathogenic vacuoles, the recruitment of intracellular organelles and inhibition of cell death. Moreover, we reconstructed a primary immune cell response by co-culturing infected organoids with neutrophils, and determined that effectors like CPAF (also known as CT858) and TepP (also known as CT875) limit the recruitment of neutrophils to infected organoids. Collectively, our model can be applied to study the cell biology of Chlamydia infections in three-dimensional structures that better reflect the diversity of cell types and polarity encountered by Chlamydia in their animal hosts.
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Affiliation(s)
- Lee Dolat
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27701, USA
| | - Raphael H Valdivia
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27701, USA
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Abstract
Chlamydia species are causative agents of sexually transmitted infections, blinding trachoma, and animal infections with zoonotic potential. Being an obligate intracellular pathogen, Chlamydia relies on the host cell for its survival and development, subverting various host cell processes throughout the infection cycle. A key subset of host proteins utilized by Chlamydia include an assortment of host kinase signaling networks which are vital for many chlamydial processes including entry, nutrient acquisition, and suppression of host cell apoptosis. In this review, we summarize the recent advancements in our understanding of host kinase subversion by Chlamydia.
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Abstract
The host-pathogen interface is a crucial battleground during bacterial infection in which host defenses are met with an array of bacterial counter-mechanisms whereby the invader aims to make the host environment more favorable to survival and dissemination. Interestingly, the eukaryotic Wnt signaling pathway has emerged as a key player in the host and pathogen tug-of-war. Although studied for decades as a regulator of embryogenesis, stem cell maintenance, bone formation, and organogenesis, Wnt signaling has recently been shown to control processes related to bacterial infection in the human host. Wnt signaling pathways contribute to cell cycle control, cytoskeleton reorganization during phagocytosis and cell migration, autophagy, apoptosis, and a number of inflammation-related events. Unsurprisingly, bacterial pathogens have evolved strategies to manipulate these Wnt-associated processes in order to enhance infection and survival within the human host. In this review, we examine the different ways human bacterial pathogens with distinct host cell tropisms and lifestyles exploit Wnt signaling for infection and address the potential of harnessing Wnt-related mechanisms to combat infectious disease.
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Affiliation(s)
- Madison R. Rogan
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - LaNisha L. Patterson
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jennifer Y. Wang
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jere W. McBride
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
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Slade JA, Brockett M, Singh R, Liechti GW, Maurelli AT. Fosmidomycin, an inhibitor of isoprenoid synthesis, induces persistence in Chlamydia by inhibiting peptidoglycan assembly. PLoS Pathog 2019; 15:e1008078. [PMID: 31622442 DOI: 10.1371/journal.ppat.1008078] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 10/29/2019] [Accepted: 09/12/2019] [Indexed: 11/19/2022] Open
Abstract
The antibiotic, fosmidomycin (FSM) targets the methylerythritol phosphate (MEP) pathway of isoprenoid synthesis by inhibiting the essential enzyme, 1-deoxy-D-xylulose 5-phosphate reductoisomerase (Dxr) and is lethal to intracellular parasites and bacteria. The obligate intracellular bacterial pathogen, Chlamydia trachomatis, alternates between two developmental forms: the extracellular, infectious elementary body (EB), and the intracellular, replicative form called the reticulate body (RB). Several stressful growth conditions including iron deprivation halt chlamydial cell division and cause development of a morphologically enlarged, but viable form termed an aberrant body (AB). This phenotype constitutes the chlamydial developmental state known as persistence. This state is reversible as removal of the stressor allows the chlamydiae to re-enter and complete the normal developmental cycle. Bioinformatic analysis indicates that C. trachomatis encodes a homolog of Dxr, but its function and the requirement for isoprenoid synthesis in chlamydial development is not fully understood. We hypothesized that chlamydial Dxr (DxrCT) is functional and that the methylerythritol phosphate (MEP) pathway is required for normal chlamydial development. Thus, FSM exposure should be lethal to C. trachomatis. Overexpression of chlamydial Dxr (DxrCT) in Escherichia coli under FSM exposure and in a conditionally lethal dxr mutant demonstrated that DxrCT functions similarly to E. coli Dxr. When Chlamydia-infected cultures were exposed to FSM, EB production was significantly reduced. However, titer recovery assays, electron microscopy, and peptidoglycan labeling revealed that FSM inhibition of isoprenoid synthesis is not lethal to C. trachomatis, but instead induces persistence. Bactoprenol is a critical isoprenoid required for peptidoglycan precursor assembly. We therefore conclude that FSM induces persistence in Chlamydia by preventing bactoprenol production necessary for peptidoglycan precursor assembly and subsequent cell division.
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Abstract
As obligate intracellular bacterial pathogens, members of the Chlamydia genera are the pivotal triggers for a wide range of infections, which can lead to blinding trachoma, pelvic inflammation, and respiratory diseases. Because of their restricted parasitism inside eukaryotic cells, the pathogens have to develop multiple strategies for adaptation with the hostile intracellular environment—intrinsically present in all host cells—to survive. The strategies that are brought into play at different stages of chlamydial development mainly involve interfering with diverse innate immune responses, such as innate immune recognition, inflammation, apoptosis, autophagy, as well as the manipulation of innate immune cells to serve as potential niches for chlamydial replication. This review will focus on the innate immune responses against chlamydial infection, highlighting the underlying molecular mechanisms used by the Chlamydia spp. to counteract host innate immune defenses. Insights into these subtle pathogenic mechanisms not only provide a rationale for the augmentation of immune responses against chlamydial infection but also open avenues for further investigation of the molecular mechanisms driving the survival of these clinically important pathogens in host innate immunity.
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Affiliation(s)
- Hongliang Chen
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China.,Department of Clinical Microbiology Laboratory, Chenzhou No. 1 People's Hospital, Chenzhou, China
| | - Yating Wen
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Zhongyu Li
- Institute of Pathogenic Biology, Hengyang Medical College, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
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Abstract
Chlamydia trachomatis is the most prevalent sexually transmitted bacterial pathogen and the leading cause of preventable blindness in the developing world.
C. trachomatis invades the epithelium of the conjunctiva and genital tract and replicates within an intracellular membrane-bound compartment termed the inclusion. To invade and replicate in mammalian cells,
Chlamydia remodels epithelial surfaces by reorganizing the cytoskeleton and cell–cell adhesions, reprograms membrane trafficking, and modulates cell signaling to dampen innate immune responses. If the infection ascends to the upper female genital tract, it can result in pelvic inflammatory disease and tissue scarring.
C. trachomatis infections are associated with infertility, ectopic pregnancies, the fibrotic disorder endometriosis, and potentially cancers of the cervix and uterus. Unfortunately, the molecular mechanisms by which this clinically important human pathogen subverts host cellular functions and causes disease have remained relatively poorly understood because of the dearth of molecular genetic tools to study
Chlamydiae and limitations of both
in vivo and
in vitro infection models. In this review, we discuss recent advances in the experimental molecular tool kit available to dissect
C. trachomatis infections with a special focus on
Chlamydia-induced epithelial barrier disruption by regulating the structure, function, and dynamics of epithelial cell–cell junctions.
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Affiliation(s)
- Lee Dolat
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
| | - Raphael H Valdivia
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
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Best A, Abu Kwaik Y. Nutrition and Bipartite Metabolism of Intracellular Pathogens. Trends Microbiol 2019; 27:550-561. [PMID: 30655036 DOI: 10.1016/j.tim.2018.12.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/20/2018] [Accepted: 12/20/2018] [Indexed: 12/29/2022]
Abstract
The host is a nutrient-rich niche for microbial pathogens, but one that comes with obstacles and challenges. Many intracellular pathogens like Legionella pneumophila, Coxiella burnetii, Listeria monocytogenes, and Chlamydia trachomatis have developed bipartite metabolism within their hosts. This style of metabolic regulation enables pathogen sensing of specific nutrients to engage them into catabolic and anabolic processes, and contributes to temporal and spatial pathogen phenotypic modulation. Not only have intracellular pathogens adapted their metabolism to the host, they have also acquired idiosyncratic strategies to exploit host nutritional supplies and intercept metabolites. Francisella tularensis and Anaplasma phagocytophilum alter host autophagy, Shigella flexneri intercepts all host pyruvate, while L. pneumophila induces host protein degradation and blocks protein translation. Strategies of pathogen manipulation of host nutrients could serve as therapeutic targets.
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Affiliation(s)
- Ashley Best
- Department of Microbiology and Immunology, College of Medicine, University of Louisville, KY, USA
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, College of Medicine, University of Louisville, KY, USA; Center for Predictive Medicine, College of Medicine, University of Louisville, KY, USA.
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