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Diallo A, Overman G, Sah P, Liechti GW. Recognition of Chlamydia trachomatis by Toll-like receptor 9 is altered during persistence. Infect Immun 2024:e0006324. [PMID: 38899879 DOI: 10.1128/iai.00063-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
Toll-like receptor 9 (TLR9) is an innate immune receptor that localizes to endosomes in antigen presenting cells and recognizes single stranded unmethylated CpG sites on bacterial genomic DNA (gDNA). Previous bioinformatic studies have demonstrated that the genome of the human pathogen Chlamydia trachomatis contains TLR9 stimulatory motifs, and correlative studies have implied a link between human TLR9 (hTLR9) genotype variants and susceptibility to infection. Here, we present our evaluation of the stimulatory potential of C. trachomatis gDNA and its recognition by hTLR9- and murine TLR9 (mTLR9)-expressing cells. Utilizing reporter cell lines, we demonstrate that purified gDNA from C. trachomatis can stimulate hTLR9 signaling, albeit at lower levels than gDNA prepared from other Gram-negative bacteria. Interestingly, we found that while C. trachomatis is capable of signaling through hTLR9 and mTLR9 during live infections in HEK293 reporter cell lines, signaling only occurs at later developmental time points. Chlamydia-specific induction of hTLR9 is blocked when protein synthesis is inhibited prior to the RB-to-EB conversion, exacerbated by the inhibition of lipooligosaccharide biosynthesis, and is significantly altered during the induction of aberrance/persistence. Our observations support the hypothesis that chlamydial gDNA is released during the conversion between the pathogen's replicative and infectious forms and during treatment with antibiotics targeting peptidoglycan assembly. Given that C. trachomatis inclusions do not co-localize with TLR9-containing vacuoles in the pro-monocytic cell line U937, our findings also hint that chlamydial gDNA is capable of egress from the inclusion, and traffics to TLR9-containing vacuoles via an as yet unknown pathway.
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Affiliation(s)
- Aissata Diallo
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Grace Overman
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - Prakash Sah
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
| | - George W Liechti
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
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2
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Challagundla N, Shah D, Dalai SK, Agrawal-Rajput R. IFNγ insufficiency during mouse intra-vaginal Chlamydia trachomatis infection exacerbates alternative activation in macrophages with compromised CD40 functions. Int Immunopharmacol 2024; 131:111821. [PMID: 38484664 DOI: 10.1016/j.intimp.2024.111821] [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: 11/04/2023] [Revised: 03/03/2024] [Accepted: 03/05/2024] [Indexed: 04/10/2024]
Abstract
Chlamydia trachomatis (C.tr), an obligate intracellular pathogen, causes asymptomatic genital infections in women and is a leading cause of preventable blindness. We have developed in vivo mouse models of acute and chronic C. trachomatis genital infection to explore the significance of macrophage-directed response in mediating immune activation/suppression. Our findings reveal that during chronic and repeated C. trachomatis infections, Th1 response is abated while Treg response is enhanced. Additionally, an increase in exhaustion (PD1, CTLA4) and anergic (Klrg3, Tim3) T cell markers is observed during chronic infection. We have also observed that M2 macrophages with low CD40 expression promote Th2 and Treg differentiation leading to sustained C. trachomatis genital infection. Macrophages infected with C. trachomatis or treated with supernatant of infected epithelial cells drive them to an M2 phenotype. C. trachomatis infection prevents the increase in CD40 expression as observed in western blots and flow cytometric analysis. Insufficient IFNγ, as observed during chronic infection, leads to incomplete clearance of bacteria and poor immune activation. C. trachomatis decapacitates IFNγ responsiveness in macrophages via hampering IFNγRI and IFNγRII expression which can be correlated with poor expression of MHC-II, CD40, iNOS and NO release even following IFNγ supplementation. M2 macrophages during C. trachomatis infection express low CD40 rendering immunosuppressive, Th2 and Treg differentiation which could not be reverted even by IFNγ supplementation. The alternative macrophages also harbour high bacterial load and are poor responders to IFNγ, thus promoting immunosuppression. In summary, C. trachomatis modulates the innate immune cells, attenuating the anti-chlamydial functions of T cells in a manner that involves decreased CD40 expression on macrophages.
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Affiliation(s)
- Naveen Challagundla
- Immunology Lab, Biological Sciences and Biotechnology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, India.
| | - Dhruvi Shah
- Immunology Lab, Biological Sciences and Biotechnology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, India.
| | - Sarat K Dalai
- Institute of Science, Nirma University, S.G. Highway, Ahmedabad, Gujarat, India.
| | - Reena Agrawal-Rajput
- Immunology Lab, Biological Sciences and Biotechnology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, India.
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3
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Wurihan W, Wang Y, Yeung S, Zou Y, Lai Z, Fondell JD, Li WV, Zhong G, Fan H. Expression activation of over 70% of Chlamydia trachomatis genes during the first hour of infection. Infect Immun 2024; 92:e0053923. [PMID: 38299827 PMCID: PMC10929459 DOI: 10.1128/iai.00539-23] [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: 01/02/2024] [Accepted: 01/09/2024] [Indexed: 02/02/2024] Open
Abstract
The obligate intracellular bacterium Chlamydia has a unique developmental cycle that alternates between two contrasting cell types. With a hardy envelope and highly condensed genome, the small elementary body (EB) maintains limited metabolic activities yet survives in extracellular environments and is infectious. After entering host cells, EBs differentiate into larger and proliferating reticulate bodies (RBs). Progeny EBs are derived from RBs in late developmental stages and eventually exit host cells. How expression of the chlamydial genome consisting of nearly 1,000 genes governs the chlamydial developmental cycle is unclear. A previous microarray study identified only 29 Chlamydia trachomatis immediate early genes, defined as genes with increased expression during the first hour postinoculation in cultured cells. In this study, we performed more sensitive RNA sequencing (RNA-Seq) analysis for C. trachomatis cultures with high multiplicities of infection. Remarkably, we observed well over 700 C. trachomatis genes that underwent 2- to 900-fold activation within 1 hour postinoculation. Quantitative reverse transcription real-time PCR analysis was further used to validate the activated expression of a large subset of the genes identified by RNA-Seq. Importantly, our results demonstrate that the immediate early transcriptome is over 20 times more extensive than previously realized. Gene ontology analysis indicates that the activated expression spans all functional categories. We conclude that over 70% of C. trachomatis genes are activated in EBs almost immediately upon entry into host cells, thus implicating their importance in initiating rapid differentiation into RBs and establishing an intracellular niche conducive with chlamydial development and growth.
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Affiliation(s)
- Wurihan Wurihan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
| | - Yuxuan Wang
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Sydney Yeung
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Yi Zou
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Zhao Lai
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, Texas, USA
- Department of Molecular Medicine, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Joseph D. Fondell
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Wei Vivian Li
- Department of Statistics, University of California Riverside, Riverside, California, USA
| | - Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Huizhou Fan
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
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Diallo A, Overman G, Sah P, Liechti GW. Recognition of Chlamydia trachomatis by Toll-Like Receptor 9 is altered during persistence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.06.579186. [PMID: 38370826 PMCID: PMC10871208 DOI: 10.1101/2024.02.06.579186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Toll-like receptor 9 (TLR9) is an innate immune receptor that localizes to endosomes in antigen presenting cells and recognizes single stranded unmethylated CpG sites on bacterial genomic DNA. Previous bioinformatic studies have indicated that the genome of the human pathogen Chlamydia trachomatis contains TLR9 stimulatory motifs, and correlative studies have implied a link between human TLR9 (hTLR9) genotype variants and susceptibility to infection. Here we present our evaluation of the stimulatory potential of C. trachomatis gDNA and its recognition by hTLR9- and murine TLR9 (mTLR9)-expressing cells. We confirm that hTLR9 colocalizes with chlamydial inclusions in the pro-monocytic cell line, U937. Utilizing HEK293 reporter cell lines, we demonstrate that purified genomic DNA from C. trachomatis can stimulate hTLR9 signaling, albeit at lower levels than gDNA prepared from other Gram-negative bacteria. Interestingly, we found that while C. trachomatis is capable of signaling through hTLR9 and mTLR9 during live infections in non-phagocytic HEK293 reporter cell lines, signaling only occurs at later developmental time points. Chlamydia-specific induction of hTLR9 is blocked when protein synthesis is inhibited prior to the RB-to-EB conversion and exacerbated by the inhibition of lipooligosaccharide biosynthesis. The induction of aberrance / persistence also significantly alters Chlamydia-specific TLR9 signaling. Our observations support the hypothesis that chlamydial gDNA is released at appreciable levels by the bacterium during the conversion between its replicative and infectious forms and during treatment with antibiotics targeting peptidoglycan assembly.
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Affiliation(s)
- Aissata Diallo
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - Grace Overman
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - Prakash Sah
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States of America
| | - George W. Liechti
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, United States of America
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5
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Jordan SJ, Wilson L, Ren J, Gupta K, Barnes S, Geisler WM. Natural Clearance of Chlamydia trachomatis Infection Is Associated With Distinct Differences in Cervicovaginal Metabolites. J Infect Dis 2023; 228:1119-1126. [PMID: 37163744 PMCID: PMC10582912 DOI: 10.1093/infdis/jiad155] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/25/2023] [Accepted: 05/09/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Natural clearance of Chlamydia trachomatis in women occurs in the interval between screening and treatment. In vitro, interferon-γ (IFN-γ)-mediated tryptophan depletion results in C. trachomatis clearance, but whether this mechanism occurs in vivo remains unclear. We previously found that women who naturally cleared C. trachomatis had lower cervicovaginal levels of tryptophan and IFN-γ compared to women with persisting infection, suggesting IFN-γ-independent pathways may promote C. trachomatis clearance. METHODS Cervicovaginal lavages from 34 women who did (n = 17) or did not (n = 17) naturally clear C. trachomatis were subjected to untargeted high-performance liquid chromatography mass-spectrometry to identify metabolites and metabolic pathways associated with natural clearance. RESULTS In total, 375 positively charged metabolites and 149 negatively charged metabolites were annotated. Compared to women with persisting infection, C. trachomatis natural clearance was associated with increased levels of oligosaccharides trehalose, sucrose, melezitose, and maltotriose, and lower levels of indoline and various amino acids. Metabolites were associated with valine, leucine, and isoleucine biosynthesis pathways. CONCLUSIONS The cervicovaginal metabolome in women who did or did not naturally clear C. trachomatis is distinct. In women who cleared C. trachomatis, depletion of various amino acids, especially valine, leucine, and isoleucine, suggests that amino acids other than tryptophan impact C. trachomatis survival in vivo.
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Affiliation(s)
- Stephen J Jordan
- Department of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Landon Wilson
- Targeted Metabolomics and Proteomics Laboratory, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jie Ren
- Department of Biostatics and Health Data Science, Indiana University, Indianapolis, Indiana, USA
| | - Kanupriya Gupta
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Stephen Barnes
- Targeted Metabolomics and Proteomics Laboratory, University of Alabama at Birmingham, Birmingham, Alabama, USA
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - William M Geisler
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Bastidas RJ, Valdivia RH. The emerging complexity of Chlamydia trachomatis interactions with host cells as revealed by molecular genetic approaches. Curr Opin Microbiol 2023; 74:102330. [PMID: 37247566 PMCID: PMC10988583 DOI: 10.1016/j.mib.2023.102330] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/31/2023]
Abstract
Chlamydia trachomatis (Ct) is an intracellular bacterial pathogen that relies on the activity of secreted proteins known as effectors to promote replication and avoidance of immune clearance. Understanding the contribution of Ct effectors to pathogenesis has proven to be challenging, given that these proteins often perform multiple functions during intracellular infection. Recent advances in molecular genetic analysis of Ct have provided valuable insights into the multifaceted nature of secreted effector proteins and their impact on the interaction between Ct and host cells and tissues. This review highlights significant findings from genetic analysis of Ct effector functions, shedding light on their diverse roles. We also discuss the challenges faced in this field of study and explore potential opportunities for further research.
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Affiliation(s)
- Robert J Bastidas
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Raphael H Valdivia
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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7
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Riffaud CM, Rucks EA, Ouellette SP. Persistence of obligate intracellular pathogens: alternative strategies to overcome host-specific stresses. Front Cell Infect Microbiol 2023; 13:1185571. [PMID: 37284502 PMCID: PMC10239878 DOI: 10.3389/fcimb.2023.1185571] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/05/2023] [Indexed: 06/08/2023] Open
Abstract
In adapting to the intracellular niche, obligate intracellular bacteria usually undergo a reduction of genome size by eliminating genes not needed for intracellular survival. These losses can include, for example, genes involved in nutrient anabolic pathways or in stress response. Living inside a host cell offers a stable environment where intracellular bacteria can limit their exposure to extracellular effectors of the immune system and modulate or outright inhibit intracellular defense mechanisms. However, highlighting an area of vulnerability, these pathogens are dependent on the host cell for nutrients and are very sensitive to conditions that limit nutrient availability. Persistence is a common response shared by evolutionarily divergent bacteria to survive adverse conditions like nutrient deprivation. Development of persistence usually compromises successful antibiotic therapy of bacterial infections and is associated with chronic infections and long-term sequelae for the patients. During persistence, obligate intracellular pathogens are viable but not growing inside their host cell. They can survive for a long period of time such that, when the inducing stress is removed, reactivation of their growth cycles resumes. Given their reduced coding capacity, intracellular bacteria have adapted different response mechanisms. This review gives an overview of the strategies used by the obligate intracellular bacteria, where known, which, unlike model organisms such as E. coli, often lack toxin-antitoxin systems and the stringent response that have been linked to a persister phenotype and amino acid starvation states, respectively.
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8
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Banerjee A, Sun Y, Muramatsu MK, Toh E, Nelson DE. A Member of an Ancient Family of Bacterial Amino Acids Transporters Contributes to Chlamydia Nutritional Virulence and Immune Evasion. Infect Immun 2023; 91:e0048322. [PMID: 36847502 PMCID: PMC10068747 DOI: 10.1128/iai.00483-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 01/31/2023] [Indexed: 03/01/2023] Open
Abstract
Many obligate intracellular bacteria, including members of the genus Chlamydia, cannot synthesize a variety of amino acids de novo and acquire these from host cells via largely unknown mechanisms. Previously, we determined that a missense mutation in ctl0225, a conserved Chlamydia open reading frame of unknown function, mediated sensitivity to interferon gamma. Here, we show evidence that CTL0225 is a member of the SnatA family of neutral amino acid transporters that contributes to the import of several amino acids into Chlamydia cells. Further, we show that CTL0225 orthologs from two other distantly related obligate intracellular pathogens (Coxiella burnetii and Buchnera aphidicola) are sufficient to import valine into Escherichia coli. We also show that chlamydia infection and interferon exposure have opposing effects on amino acid metabolism, potentially explaining the relationship between CTL0225 and interferon sensitivity. Overall, we show that phylogenetically diverse intracellular pathogens use an ancient family of amino acid transporters to acquire host amino acids and provide another example of how nutritional virulence and immune evasion can be linked in obligate intracellular pathogens.
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Affiliation(s)
- Arkaprabha Banerjee
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Yuan Sun
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Matthew K. Muramatsu
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Evelyn Toh
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - David E. Nelson
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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9
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Intracellular lifestyle of Chlamydia trachomatis and host-pathogen interactions. Nat Rev Microbiol 2023:10.1038/s41579-023-00860-y. [PMID: 36788308 DOI: 10.1038/s41579-023-00860-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2023] [Indexed: 02/16/2023]
Abstract
In recent years, substantial progress has been made in the understanding of the intracellular lifestyle of Chlamydia trachomatis and how the bacteria establish themselves in the human host. As an obligate intracellular pathogenic bacterium with a strongly reduced coding capacity, C. trachomatis depends on the provision of nutrients from the host cell. In this Review, we summarize the current understanding of how C. trachomatis establishes its intracellular replication niche, how its metabolism functions in the host cell, how it can defend itself against the cell autonomous and innate immune response and how it overcomes adverse situations through the transition to a persistent state. In particular, we focus on those processes for which a mechanistic understanding has been achieved.
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10
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Wang L, Hou Y, Yuan H, Chen H. The role of tryptophan in Chlamydia trachomatis persistence. Front Cell Infect Microbiol 2022; 12:931653. [PMID: 35982780 PMCID: PMC9378776 DOI: 10.3389/fcimb.2022.931653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/14/2022] [Indexed: 11/26/2022] Open
Abstract
Chlamydia trachomatis (C. trachomatis) is the most common etiological agent of bacterial sexually transmitted infections (STIs) and a worldwide public health issue. The natural course with C. trachomatis infection varies widely between individuals. Some infections clear spontaneously, others can last for several months or some individuals can become reinfected, leading to severe pathological damage. Importantly, the underlying mechanisms of C. trachomatis infection are not fully understood. C. trachomatis has the ability to adapt to immune response and persist within host epithelial cells. Indoleamine-2,3-dioxygenase (IDO) induced by interferon-gamma (IFN-γ) degrades the intracellular tryptophan pool, to which C. trachomatis can respond by converting to a non-replicating but viable state. C. trachomatis expresses and encodes for the tryptophan synthase (TS) genes (trpA and trpB) and tryptophan repressor gene (trpR). Multiple genes interact to regulate tryptophan synthesis from exogenous indole, and persistent C. trachomatis can recover its infectivity by converting indole into tryptophan. In this review, we discuss the characteristics of chlamydial infections, biosynthesis and regulation of tryptophan, the relationship between tryptophan and C. trachomatis, and finally, the links between the tryptophan/IFN-γ axis and C. trachomatis persistence.
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Affiliation(s)
- Li Wang
- The First School of Clinical Medicine, Chenzhou No.1 People’s Hospital, Southern Medical University, Guangzhou, China
- Department of Clinical Microbiology Laboratory, Chenzhou No.1 People’s Hospital, Chenzhou, China
| | - YingLan Hou
- The First School of Clinical Medicine, Chenzhou No.1 People’s Hospital, Southern Medical University, Guangzhou, China
- Department of Clinical Microbiology Laboratory, Chenzhou No.1 People’s Hospital, Chenzhou, China
| | - HongXia Yuan
- The First School of Clinical Medicine, Chenzhou No.1 People’s Hospital, Southern Medical University, Guangzhou, China
- Department of Clinical Microbiology Laboratory, Chenzhou No.1 People’s Hospital, Chenzhou, China
| | - Hongliang Chen
- The First School of Clinical Medicine, Chenzhou No.1 People’s Hospital, Southern Medical University, Guangzhou, China
- Department of Clinical Microbiology Laboratory, Chenzhou No.1 People’s Hospital, Chenzhou, China
- *Correspondence: Hongliang Chen,
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Huang X, Liufu Q, Xu R, Chen X, Liu M, Han J, Guan H, Ma C. Integrating lncRNAs and mRNAs Expression Profiles in Penicillin-Induced Persistent Chlamydial Infection in HeLa Cells. Front Mol Biosci 2022; 9:744901. [PMID: 35252346 PMCID: PMC8890745 DOI: 10.3389/fmolb.2022.744901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
Chlamydia trachomatis (C. trachomatis) is a major etiological agent of sexually transmitted infection. Some stressing conditions can result in persistent chlamydial infection, which is thought to be associated with severe complications including ectopic pregnancy and tubal factor infertility. Long noncoding RNAs (lncRNAs) have been identified as key modulators in many biological processes. Nevertheless, the role of lncRNAs in persistent chlamydial infection is still unclear. In this study, we used lncRNA and mRNA microarray to identify the global lncRNAs and mRNAs expression in penicillin-induced persistent chlamydial infection in HeLa cells as well as the control group (HeLa cells without C. trachomatis infection). Among 1005 differentially expressed lncRNAs, 585 lncRNAs were upregulated and 420 downregulated in persistent chlamydial infection, while 410 mRNAs were identified to express differentially, of which 113 mRNAs were upregulated and 297 downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis with differentially expressed genes were performed. We then constructed the lncRNA-miRNA-mRNA competing endogenous RNAs (ceRNAs) network. Four mRNAs were validated to be changed by quantitative real-time PCR which were correlated with the microarray result. Integration of protein-protein interaction network was constructed and hub genes were identified. These findings provide a new perspective on the molecular mechanisms of penicillin-induced persistent chlamydial infection.
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Affiliation(s)
- Xiaobao Huang
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Qian Liufu
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Rui Xu
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiaohong Chen
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Mingna Liu
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jiande Han
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hongyu Guan
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Chunguang Ma, ; Hongyu Guan,
| | - Chunguang Ma
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Chunguang Ma, ; Hongyu Guan,
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12
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Persistence Alters the Interaction between Chlamydia trachomatis and Its Host Cell. Infect Immun 2021; 89:e0068520. [PMID: 34001559 DOI: 10.1128/iai.00685-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In response to stress, the obligate intracellular pathogen Chlamydia trachomatis stops dividing and halts its biphasic developmental cycle. The infectious, extracellular form of this bacterium is highly susceptible to killing by the host immune response, and by pausing development, Chlamydia can survive in an intracellular, "aberrant" state for extended periods of time. The relevance of these aberrant forms has long been debated, and many questions remain concerning how they contribute to the persistence and pathogenesis of the organism. Using reporter cell lines, fluorescence microscopy, and a dipeptide labeling strategy, we measured the ability of C. trachomatis to synthesize, assemble, and degrade peptidoglycan under various aberrance-inducing conditions. We found that all aberrance-inducing conditions affect chlamydial peptidoglycan and that some actually halt the biosynthesis pathway early enough to prevent the release of an immunostimulatory peptidoglycan component, muramyl tripeptide. In addition, utilizing immunofluorescence and electron microscopy, we determined that the induction of aberrance can detrimentally affect the development of the microbe's pathogenic vacuole (the inclusion). Taken together, our data indicate that aberrant forms of Chlamydia generated by different environmental stressors can be sorted into two broad categories based on their ability to continue releasing peptidoglycan-derived, immunostimulatory muropeptides and their ability to secrete effector proteins that are normally expressed at the mid- and late stages of the microbe's developmental cycle. Our findings reveal a novel, immunoevasive feature inherent to a subset of aberrant chlamydial forms and provide clarity and context to the numerous persistence mechanisms employed by these ancient, genetically reduced microbes.
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13
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Huang X, Tan J, Chen X, Liu M, Zhu H, Li W, He Z, Han J, Ma C. Akt Phosphorylation Influences Persistent Chlamydial Infection and Chlamydia-Induced Golgi Fragmentation Without Involving Rab14. Front Cell Infect Microbiol 2021; 11:675890. [PMID: 34169005 PMCID: PMC8218875 DOI: 10.3389/fcimb.2021.675890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 04/29/2021] [Indexed: 11/30/2022] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that causes multiple diseases involving the eyes, gastrointestinal tract, and genitourinary system. Previous studies have identified that in acute chlamydial infection, C. trachomatis requires Akt pathway phosphorylation and Rab14-positive vesicles to transmit essential lipids from the Golgi apparatus in survival and replication. However, the roles that Akt phosphorylation and Rab14 play in persistent chlamydial infection remain unclear. Here, we discovered that the level of Akt phosphorylation was lower in persistent chlamydial infection, and positively correlated with the effect of activating the development of Chlamydia but did not change the infectivity and 16s rRNA gene expression. Rab14 was found to exert a limited effect on persistent infection. Akt phosphorylation might regulate Chlamydia development and Chlamydia-induced Golgi fragmentation in persistent infection without involving Rab14. Our results provide a new insight regarding the potential of synergistic repressive effects of an Akt inhibitor with antibiotics in the treatment of persistent chlamydial infection induced by penicillin.
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Affiliation(s)
- Xiaobao Huang
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jinfeng Tan
- Department of Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiaohong Chen
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Mingna Liu
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Huiling Zhu
- Department of Dermatology, The First Affiliated Hospital of Guangzhou Medical College, Guangzhou, China
| | - Wenjing Li
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhenjian He
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Jiande Han
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Chunguang Ma
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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14
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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.
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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
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15
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Genome copy number regulates inclusion expansion, septation, and infectious developmental form conversion in Chlamydia trachomatis. J Bacteriol 2021; 203:JB.00630-20. [PMID: 33431433 PMCID: PMC8095454 DOI: 10.1128/jb.00630-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
DNA replication is essential for the growth and development of Chlamydia trachomatis, however it is unclear how this process contributes to and is controlled by the pathogen's biphasic lifecycle. While inhibitors of transcription, translation, cell division, and glucose-6-phosphate transport all negatively affect chlamydial intracellular development, the effects of directly inhibiting DNA polymerase have never been examined. We isolated a temperature sensitive dnaE mutant (dnaEts ) that exhibits a ∼100-fold reduction in genome copy number at the non-permissive temperature (40°C), but replicates similarly to the parent at the permissive temperature of 37°C. We measured higher ratios of genomic DNA nearer the origin of replication than the terminus in dnaEts at 40°C, indicating that this replication deficiency is due to a defect in DNA polymerase processivity. dnaEts formed fewer and smaller pathogenic vacuoles (inclusions) at 40°C, and the bacteria appeared enlarged and exhibited defects in cell division. The bacteria also lacked both discernable peptidoglycan and polymerized MreB, the major cell division organizing protein in Chlamydia responsible for nascent peptidoglycan biosynthesis. We also found that absolute genome copy number, rather than active genome replication, was sufficient for infectious progeny production. Deficiencies in both genome replication and inclusion expansion reversed when dnaEts was shifted from 40°C to 37°C early in infection, and intragenic suppressor mutations in dnaE also restored dnaEts genome replication and inclusion expansion at 40°C. Overall, our results show that genome replication in C. trachomatis is required for inclusion expansion, septum formation, and the transition between the microbe's replicative and infectious forms.SIGNIFICANCE Chlamydiae transition between infectious, extracellular elementary bodies (EBs) and non-infectious, intracellular reticulate bodies (RBs). Some checkpoints that govern transitions in chlamydial development have been identified, but the extent to which genome replication plays a role in regulating the pathogen's infectious cycle has not been characterized. We show that genome replication is dispensable for EB to RB conversion, but is necessary for RB proliferation, division septum formation, and inclusion expansion. We use new methods to investigate developmental checkpoints and dependencies in Chlamydia that facilitate the ordering of events in the microbe's biphasic life cycle. Our findings suggest that Chlamydia utilizes feedback inhibition to regulate core metabolic processes during development, likely an adaptation to intracellular stress and a nutrient-limiting environment.
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16
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Eisenreich W, Rudel T, Heesemann J, Goebel W. Persistence of Intracellular Bacterial Pathogens-With a Focus on the Metabolic Perspective. Front Cell Infect Microbiol 2021; 10:615450. [PMID: 33520740 PMCID: PMC7841308 DOI: 10.3389/fcimb.2020.615450] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022] Open
Abstract
Persistence has evolved as a potent survival strategy to overcome adverse environmental conditions. This capability is common to almost all bacteria, including all human bacterial pathogens and likely connected to chronic infections caused by some of these pathogens. Although the majority of a bacterial cell population will be killed by the particular stressors, like antibiotics, oxygen and nitrogen radicals, nutrient starvation and others, a varying subpopulation (termed persisters) will withstand the stress situation and will be able to revive once the stress is removed. Several factors and pathways have been identified in the past that apparently favor the formation of persistence, such as various toxin/antitoxin modules or stringent response together with the alarmone (p)ppGpp. However, persistence can occur stochastically in few cells even of stress-free bacterial populations. Growth of these cells could then be induced by the stress conditions. In this review, we focus on the persister formation of human intracellular bacterial pathogens, some of which belong to the most successful persister producers but lack some or even all of the assumed persistence-triggering factors and pathways. We propose a mechanism for the persister formation of these bacterial pathogens which is based on their specific intracellular bipartite metabolism. We postulate that this mode of metabolism ultimately leads, under certain starvation conditions, to the stalling of DNA replication initiation which may be causative for the persister state.
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Affiliation(s)
- Wolfgang Eisenreich
- Department of Chemistry, Chair of Biochemistry, Technische Universität München, Garching, Germany
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
| | - Werner Goebel
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
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17
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Panzetta ME, Luján AL, Bastidas RJ, Damiani MT, Valdivia RH, Saka HA. Ptr/CTL0175 Is Required for the Efficient Recovery of Chlamydia trachomatis From Stress Induced by Gamma-Interferon. Front Microbiol 2019; 10:756. [PMID: 31024512 PMCID: PMC6467971 DOI: 10.3389/fmicb.2019.00756] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 03/26/2019] [Indexed: 12/26/2022] Open
Abstract
Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen in humans and a frequent cause of asymptomatic, persistent infections leading to serious complications, particularly in young women. Chlamydia displays a unique obligate intracellular lifestyle involving the infectious elementary body and the replicative reticulate body. In the presence of stressors such as gamma-interferon (IFNγ) or beta-lactam antibiotics, C. trachomatis undergoes an interruption in its replication cycle and enters a viable but non-cultivable state. Upon removal of the stressors, surviving C. trachomatis resume cell division and developmental transitions. In this report, we describe a genetic screen to identify C. trachomatis mutants with defects in recovery from IFNγ- and/or penicillin-induced stress and characterized a chemically derived C. trachomatis mutant strain that exhibited a significant decrease in recovery from IFNγ- but not penicillin-induced stress. Through lateral gene transfer and targeted insertional gene inactivation we identified ptr, encoding a predicted protease, as a gene required for recovery from IFNγ-induced stress. A C. trachomatis LGV-L2 ptr-null strain displayed reduced generation of infectious progeny and impaired genome replication upon removal of IFNγ. This defect was restored by introducing a wild type copy of ptr on a plasmid, indicating that Ptr is required for a rapid growth upon removal of IFNγ. Ptr was expressed throughout the developmental cycle and localized to the inclusion lumen. Overall, our findings indicate that the putative secreted protease Ptr is required for C. trachomatis to specifically recover from IFNγ- but not penicillin-induced stress.
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Affiliation(s)
- María E Panzetta
- Centro de Investigaciones en Bioquímica Clínica e Inmunología, CONICET, Córdoba, Argentina.,Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Agustín L Luján
- Instituto de Medicina y Biología Experimental de Cuyo, CONICET, Mendoza, Argentina.,Área de Química Biológica, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Robert J Bastidas
- Center for Host-Microbe Interactions, Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
| | - María T Damiani
- Instituto de Medicina y Biología Experimental de Cuyo, CONICET, Mendoza, Argentina.,Área de Química Biológica, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Raphael H Valdivia
- Center for Host-Microbe Interactions, Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
| | - Héctor A Saka
- Centro de Investigaciones en Bioquímica Clínica e Inmunología, CONICET, Córdoba, Argentina.,Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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18
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Genetic Screen in Chlamydia muridarum Reveals Role for an Interferon-Induced Host Cell Death Program in Antimicrobial Inclusion Rupture. mBio 2019; 10:mBio.00385-19. [PMID: 30967464 PMCID: PMC6456753 DOI: 10.1128/mbio.00385-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Multiple obligatory intracellular bacteria in the genus Chlamydia are important pathogens. In humans, strains of C. trachomatis cause trachoma, chlamydia, and lymphogranuloma venereum. These diseases are all associated with extended courses of infection and reinfection that likely reflect the ability of chlamydiae to evade various aspects of host immune responses. Interferon-stimulated genes, driven in part by the cytokine interferon gamma, restrict the host range of various Chlamydia species, but how these pathogens evade interferon-stimulated genes in their definitive host is poorly understood. Various Chlamydia species can inhibit death of their host cells and may have evolved this strategy to evade prodeath signals elicited by host immune responses. We present evidence that chlamydia-induced programmed cell death resistance evolved to counter interferon- and immune-mediated killing of Chlamydia-infected cells. Interferon-regulated immune defenses protect mammals from pathogenically diverse obligate intracellular bacterial pathogens of the genus Chlamydia. Interferon gamma (IFN-γ) is especially important in controlling the virulence of Chlamydia species and thus impacts the modeling of human chlamydial infection and disease in mice. How IFN-γ contributes to cell-autonomous defenses against Chlamydia species and how these pathogens evade IFN-γ-mediated immunity in their natural hosts are not well understood. We conducted a genetic screen which identified 31 IFN-γ-sensitive (Igs) mutants of the mouse model pathogen Chlamydia muridarum. Genetic suppressor analysis and lateral gene transfer were used to map the phenotype of one of these mutants, Igs4, to a missense mutation in a putative chlamydial inclusion membrane protein, TC0574. We observed the lytic destruction of Igs4-occupied inclusions and accompanying host cell death in response to IFN-γ priming or various proapoptotic stimuli. However, Igs4 was insensitive to IFN-γ-regulated cell-autonomous defenses previously implicated in anti-Chlamydia trachomatis host defense in mice. Igs4 inclusion integrity was restored by caspase inhibitors, indicating that the IFN-γ-mediated destruction of Igs4 inclusions is dependent upon the function of caspases or related prodeath cysteine proteases. We further demonstrated that the Igs4 mutant is immune restricted in an IFN-γ-dependent manner in a mouse infection model, thereby implicating IFN-γ-mediated inclusion destruction and host cell death as potent in vivo host defense mechanisms to which wild-type C. muridarum is resistant. Overall, our results suggest that C. muridarum evolved resistance mechanisms to counter IFN-γ-elicited programmed cell death and the associated destruction of intravacuolar pathogens.
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19
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Abstract
Chlamydia is a major etiological agent of human disease that affects millions of individuals worldwide. Historically, our understanding of the mechanisms that contribute to its pathogenesis has been limited. However, the recent development of powerful genetic tools for manipulating Chlamydia has resulted in significant gains in our ability to dissect its virulence mechanisms. These tools have overcome several barriers for manipulating intracellular pathogens and are amenable for the routine genetic engineering of Chlamydia. Here, we provide several detailed protocols for performing genetic analysis in Chlamydia trachomatis allowing investigators to elucidate how this obligate intracellular pathogen causes disease.
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20
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Panzetta ME, Valdivia RH, Saka HA. Chlamydia Persistence: A Survival Strategy to Evade Antimicrobial Effects in-vitro and in-vivo. Front Microbiol 2018; 9:3101. [PMID: 30619180 PMCID: PMC6299033 DOI: 10.3389/fmicb.2018.03101] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 11/30/2018] [Indexed: 11/13/2022] Open
Abstract
The Chlamydiaceae comprise a group of highly adapted bacterial pathogens sharing a unique intracellular lifestyle. Three Chlamydia species are pathogenic to humans: Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci. C. trachomatis is the leading bacterial cause of sexually-transmitted infections and infectious blindness worldwide. Chlamydia pneumoniae is a major cause of community-acquired atypical pneumonia. C. psittaci primarily affects psittacine birds and can be transmitted to humans causing psittacosis, a potentially fatal form of pneumonia. As opposed to other bacterial pathogens, the spread of clinically relevant antimicrobial resistance genes does not seem to be a major problem for the treatment of Chlamydia infections. However, when exposed to stressing conditions, like those arising from exposure to antimicrobial stimuli, these bacteria undergo a temporary interruption in their replication cycle and enter a viable but non-cultivable state known as persistence. When the stressing conditions are removed, Chlamydia resumes replication and generation of infectious particles. This review gives an overview of the different survival strategies used by Chlamydia to evade the deleterious effects of penicillin and IFNγ, with a focus on the different models used to study Chlamydia persistence, their contribution to elucidating the molecular basis of this complex phenomenon and their potential implications for studies in animal models of infection.
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Affiliation(s)
- Maria Emilia Panzetta
- CIBICI-CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Raphael H. Valdivia
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, United States
| | - Hector Alex Saka
- CIBICI-CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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21
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Yazaki T, Sato S, Tobita H, Isoda K, Miyake T, Kinoshita Y. Elderly Fitz-Hugh-Curtis syndrome observed with superb microvascular imaging system. J Med Ultrason (2001) 2018; 45:611-615. [PMID: 29464468 DOI: 10.1007/s10396-018-0865-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 01/09/2018] [Indexed: 11/09/2022]
Abstract
Fitz-Hugh-Curtis syndrome (FHCS) is defined as inflammation on the surface of the liver following sexually transmitted chlamydia infection. We successfully observed the microvascular structure of the inflamed portion between the abdominal wall and surface of the liver in an elderly patient with FHCS using a superb microvascular imaging (SMI) system, a new technology developed for observing minute vascular flow. An 80-year-old Japanese female with right dorsal to lateral abdominal pain and fever came to our hospital. Anti-chlamydia antibodies were positive. SMI revealed signals suggesting small vessels passing from the liver surface to the hypoechoic space.
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Affiliation(s)
- Tomotaka Yazaki
- Department of Hepatology, Faculty of Medicine, Shimane University, Izumo, Japan
| | - Shuichi Sato
- Department of Hepatology, Faculty of Medicine, Shimane University, Izumo, Japan. .,Department of Gastroenterology and Hepatology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane, Japan.
| | - Hiroshi Tobita
- Department of Hepatology, Faculty of Medicine, Shimane University, Izumo, Japan
| | - Kazuki Isoda
- Department of Hepatology, Faculty of Medicine, Shimane University, Izumo, Japan
| | - Tatsuya Miyake
- Department of Hepatology, Shimane Prefectural Hospital, Izumo, Japan
| | - Yoshikazu Kinoshita
- Department of Gastroenterology, Faculty of Medicine, Shimane University, Izumo, Japan
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22
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Transformation of Chlamydia: current approaches and impact on our understanding of chlamydial infection biology. Microbes Infect 2018; 20:445-450. [PMID: 29409975 DOI: 10.1016/j.micinf.2018.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 01/04/2018] [Accepted: 01/05/2018] [Indexed: 12/11/2022]
Abstract
The intonation "The king is dead, long live the king" aptly describes the state of Chlamydia research. Genetic-based approaches are rapidly replacing correlative strategies to provide new insights. We describe how current transformation technologies are enhancing progress in understanding Chlamydia infection biology and present key opportunities for further development.
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23
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Chlamydia trachomatis: the Persistent Pathogen. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00203-17. [PMID: 28835360 DOI: 10.1128/cvi.00203-17] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium whose only natural host is humans. Although presenting as asymptomatic in most women, genital tract chlamydial infections are a leading cause of pelvic inflammatory disease, tubal factor infertility, and ectopic pregnancy. C. trachomatis has evolved successful mechanisms to avoid destruction by autophagy and the host immune system and persist within host epithelial cells. The intracellular form of this organism, the reticulate body, can enter into a persistent nonreplicative but viable state under unfavorable conditions. The infectious form of the organism, the elementary body, is again generated when the immune attack subsides. In its persistent form, C. trachomatis ceases to produce its major structural and membrane components, but synthesis of its 60-kDa heat shock protein (hsp60) is greatly upregulated and released from the cell. The immune response to hsp60, perhaps exacerbated by repeated cycles of productive infection and persistence, may promote damage to fallopian tube epithelial cells, scar formation, and tubal occlusion. The chlamydial and human hsp60 proteins are very similar, and hsp60 is one of the first proteins produced by newly formed embryos. Thus, the development of immunity to epitopes in the chlamydial hsp60 that are also present in the corresponding human hsp60 may increase susceptibility to pregnancy failure in infected women. Delineation of host factors that increase the likelihood that C. trachomatis will avoid immune destruction and survive within host epithelial cells and utilization of this knowledge to design individualized preventative and treatment protocols are needed to more effectively combat infections by this persistent pathogen.
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24
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Advances and Obstacles in the Genetic Dissection of Chlamydial Virulence. Curr Top Microbiol Immunol 2017; 412:133-158. [PMID: 29090367 DOI: 10.1007/82_2017_76] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Obligate intracellular pathogens in the family Chlamydiaceae infect taxonomically diverse eukaryotes ranging from amoebae to mammals. However, many fundamental aspects of chlamydial cell biology and pathogenesis remain poorly understood. Genetic dissection of chlamydial biology has historically been hampered by a lack of genetic tools. Exploitation of the ability of chlamydia to recombine genomic material by lateral gene transfer (LGT) ushered in a new era in chlamydia research. With methods to map mutations in place, genetic screens were able to assign functions and phenotypes to specific chlamydial genes. Development of an approach for stable transformation of chlamydia also provided a mechanism for gene delivery and platforms for disrupting chromosomal genes. Here, we explore how these and other tools have been used to test hypotheses concerning the functions of known chlamydial virulence factors and discover the functions of completely uncharacterized genes. Refinement and extension of the existing genetic tools to additional Chlamydia spp. will substantially advance understanding of the biology and pathogenesis of this important group of pathogens.
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25
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Zhong G. Chlamydial Plasmid-Dependent Pathogenicity. Trends Microbiol 2016; 25:141-152. [PMID: 27712952 DOI: 10.1016/j.tim.2016.09.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/11/2016] [Accepted: 09/19/2016] [Indexed: 10/20/2022]
Abstract
Most Chlamydia species carry a 7.5kb plasmid encoding eight open reading frames conventionally called plasmid glycoproteins 1-8 or pGP1-8. Although the plasmid is not critical for chlamydial growth in vitro, its role in chlamydial pathogenesis is clearly demonstrated in the genital tracts of mice infected with Chlamydia muridarum, a model for investigating the human pathogen Chlamydia trachomatis. Plasmid-free C. trachomatis is also attenuated in both the mouse genital tract and nonhuman primate ocular tissue. Deficiency in pGP3 alone, which is regulated by pGP4, largely reproduced the in vivo but not in vitro phenotypes of the plasmid-free organisms, suggesting that pGP3 is a key in vivo virulence factor. The positive and negative regulations of some chromosomal genes by pGP4 and pGP5, respectively, may allow the plasmid to promote chlamydial adaptation to varied animal tissue environments. The focus of this review is to summarize the progress on the pathogenic functions of the plasmid-encoded open reading frames, which may motivate further investigation of the molecular mechanisms of chlamydial pathogenicity and development of medical utility of the chlamydial plasmid system.
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Affiliation(s)
- Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
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