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Tian Q, Zhang T, Shu C, Han Z, Huang Y, Wan J, Wang L, Sun X. Diverse animal models for Chlamydia infections: unraveling pathogenesis through the genital and gastrointestinal tracts. Front Microbiol 2024; 15:1386343. [PMID: 38605708 PMCID: PMC11007077 DOI: 10.3389/fmicb.2024.1386343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 03/18/2024] [Indexed: 04/13/2024] Open
Abstract
Chlamydia trachomatis is responsible for infections in various mucosal tissues, including the eyes, urogenital, respiratory, and gastrointestinal tracts. Chronic infections can result in severe consequences such as blindness, ectopic pregnancy, and infertility. The underlying mechanisms leading to these diseases involve sustained inflammatory responses, yet thorough comprehension of the underlying mechanisms remains elusive. Chlamydial biologists employ in multiple methods, integrating biochemistry, cell biology, and genetic tools to identify bacterial factors crucial for host cell interactions. While numerous animal models exist to study chlamydial pathogenesis and assess vaccine efficacy, selecting appropriate models for biologically and clinically relevant insights remains a challenge. Genital infection models in animals have been pivotal in unraveling host-microbe dynamics, identifying potential chlamydial virulence factors influencing genital pathogenicity. However, the transferability of this knowledge to human pathogenic mechanisms remains uncertain. Many putative virulence factors lack assessment in optimal animal tissue microenvironments, despite the diverse chlamydial infection models available. Given the propensity of genital Chlamydia to spread to the gastrointestinal tract, investigations into the pathogenicity and immunological impact of gut Chlamydia become imperative. Notably, the gut emerges as a promising site for both chlamydial infection vaccination and pathogenesis. This review elucidates the pathogenesis of Chlamydia infections and delineates unique features of prevalent animal model systems. The primary focus of this review is to consolidate and summarize current animal models utilized in Chlamydia researches, presenting findings, discussions on their contributions, and suggesting potential directions for further studies.
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Affiliation(s)
- Qi Tian
- Department of Obstetrics & Gynecology, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
- National Health Commission Key Laboratory for Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
| | - Tianyuan Zhang
- Key Lab of Molecular Virology and Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, China
| | - Chuqiang Shu
- Department of Obstetrics & Gynecology, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
- National Health Commission Key Laboratory for Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
| | - Zixuan Han
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Youyou Huang
- Department of Obstetrics & Gynecology, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
| | - Jiao Wan
- Department of Obstetrics & Gynecology, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
| | - Luying Wang
- Department of Obstetrics and Gynecology, 3rd Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xin Sun
- Department of Obstetrics and Gynecology, 3rd Xiangya Hospital, Central South University, Changsha, Hunan, China
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Cheong HC, Cheok YY, Chan YT, Tang TF, Sulaiman S, Looi CY, Gupta R, Arulanandam B, Chang LY, Wong WF. Chlamydia trachomatis plasmid-encoding Pgp3 protein induces secretion of distinct inflammatory signatures from HeLa cervical epithelial cells. BMC Microbiol 2023; 23:58. [PMID: 36870960 PMCID: PMC9985209 DOI: 10.1186/s12866-023-02802-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND Genital Chlamydia trachomatis infection is the most common bacterial sexual transmitted disease that causes severe complications including pelvic inflammatory disease, ectopic pregnancy, and infertility in females. The Pgp3 protein encoded by C. trachomatis plasmid has been speculated to be an important player in chlamydial pathogenesis. However, the precise function of this protein is unknown and thus remains to be thoroughly investigated. METHODS In this study, we synthesized Pgp3 protein for in vitro stimulation in the Hela cervical carcinoma cells. RESULTS AND CONCLUSION We showed that Pgp3 induced prominent expression of host inflammatory cytokine genes including interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha-induced protein 3 (TNFAIP3), and chemokine C-X-C motif ligand 1 (CXCL1), implying a possible role of Pgp3 in modulating the inflammatory reaction in the host.
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Affiliation(s)
- Heng Choon Cheong
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yi Ying Cheok
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yee Teng Chan
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Ting Fang Tang
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Sofiah Sulaiman
- Department of Obstetrics and Gynecology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Chung Yeng Looi
- School of Biosciences, Faculty of Health and Medical Sciences, Taylor's University, 47500, Subang Jaya, Selangor, Malaysia
| | - Rishein Gupta
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA
| | - Bernard Arulanandam
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA.,Department of Immunology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Li-Yen Chang
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Won Fen Wong
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
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Tian Q, Zhang T, Wang L, Ma J, Sun X. Gut dysbiosis contributes to chlamydial induction of hydrosalpinx in the upper genital tract. Front Microbiol 2023; 14:1142283. [PMID: 37125189 PMCID: PMC10133527 DOI: 10.3389/fmicb.2023.1142283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/23/2023] [Indexed: 05/02/2023] Open
Abstract
Chlamydia trachomatis is one of the most common sexually infections that cause infertility, and its genital infection induces tubal adhesion and hydrosalpinx. Intravaginal Chlamydia muridarum infection in mice can induce hydrosalpinx in the upper genital tract and it has been used for studying C. trachomatis pathogenicity. DBA2/J strain mice were known to be resistant to the chlamydial induction of hydrosalpinx. In this study, we took advantage of this feature of DBA2/J mice to evaluate the role of antibiotic induced dysbiosis in chlamydial pathogenicity. Antibiotics (vancomycin and gentamicin) were orally administrated to induce dysbiosis in the gut of DBA2/J mice. The mice with or without antibiotic treatment were evaluated for gut and genital dysbiosis and then intravaginally challenged by C. muridarum. Chlamydial burden was tested and genital pathologies were evaluated. We found that oral antibiotics significantly enhanced chlamydial induction of genital hydrosalpinx. And the antibiotic treatment induced severe dysbiosis in the GI tract, including significantly reduced fecal DNA and increased ratios of firmicutes over bacteroidetes. The oral antibiotic did not alter chlamydial infection or microbiota in the mouse genital tracts. Our study showed that the oral antibiotics-enhanced hydrosalpinx correlated with dysbiosis in gut, providing the evidence for associating gut microbiome with chlamydial genital pathogenicity.
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Affiliation(s)
- Qi Tian
- Department of Obstetrics and Gynecology, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
- National Health Commission Key Laboratory for Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
- *Correspondence: Qi Tian,
| | - Tianyuan Zhang
- Key Lab of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
- Tianyuan Zhang,
| | - Luying Wang
- Department of Obstetrics and Gynecology, Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jingyue Ma
- Department of Dermatovenereology, Tianjin Medical University General Hospital, Tianjin, China
| | - Xin Sun
- Department of Obstetrics and Gynecology, Third Xiangya Hospital, Central South University, Changsha, Hunan, China
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Xu Y, Wang J. Chlamydia
transmitting from the genital to gastrointestinal tract and inducing tubal disease: Double attack pattern. ZHONG NAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF CENTRAL SOUTH UNIVERSITY. MEDICAL SCIENCES 2022; 47:1275-1280. [PMID: 36411712 PMCID: PMC10930326 DOI: 10.11817/j.issn.1672-7347.2022.220023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Indexed: 06/16/2023]
Abstract
Chlamydia trachomatis ( CT ) genital tract infection is insidious, and patients often have no conscious symptoms.Delayed treatment after infection can lead to serious complications. Chlamydia muridarum ( CM ) genital tract infection in female mice can simulate CT genital tract infection in women, which is an ideal model to investigate the pathogenesis of CT . CM plasmid protein pGP3, chromosomal protein TC0237/TC0668, CM -specific CD8 + T cells, TNF-α, and IL-13 can induce genital tract inflammation, CD4 + T cells are responsible for CM clearance. However, tubal inflammation persists after genital tract CM is removed. Genital tract CM can spread spontaneously in vivo and colonize the gastrointestinal (GI) tract, but the GI tract CM cannot reverse spread to the genital tract. The survival time and number of CM transmitted from genital tract to GI tract are positively correlated with the long-term lesion of oviduct, while the CM inoculated directly into the GI tract has no pathogenicity in both the genital and GI tract. The double attack pattern of Chlamydia -induced genital tract inflammatory lesions is as follows: CM infection of oviduct epithelial cells initiates the process of oviduct repair as the first attack. After genital CM spreads to the GI tract, activated chlamydia-specific CD8 + T cells are recruited to the genital tract and secreted pro-fibrotic cytokines such as TNF-α and IL-13. This process is called the second attack which transform tubal repair initiated by the first attack into long-term tubal fibrosis/hydrosalpinx. Elucidating the pathogenic mechanism of Chlamydia infection can provide new ideas for the development of Chlamydia vaccine, which is expected to solve the problems of infertility caused by repeated CT infection in women.
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Affiliation(s)
- Ying Xu
- Department of Immunology, School of Basic Medical Science, Central South University, Changsha 410078, China.
| | - Jie Wang
- Department of Immunology, School of Basic Medical Science, Central South University, Changsha 410078, China.
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Characterization of pathogenic CD8 + T cells in Chlamydia-infected OT1 mice. Infect Immun 2021; 90:e0045321. [PMID: 34724387 DOI: 10.1128/iai.00453-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chlamydia trachomatis is a leading infectious cause of infertility in women due to its induction of lasting pathology such as hydrosalpinx. Chlamydia muridarum induces mouse hydrosalpinx because C. muridarum can both invade tubal epithelia directly (as a 1st hit) and induce lymphocytes to promote hydrosalpinx indirectly (as a 2nd hit). In the current study, a critical role of CD8+ T cells in chlamydial induction of hydrosalpinx was validated in both wild type C57BL/6J and OT1 transgenic mice. OT1 mice failed to develop hydrosalpinx partially due to the failure of their lymphocytes to recognize chlamydial antigens. CD8+ T cells from naïve C57BL/6J rescued the recipient OT1 mice to develop hydrosalpinx when naïve CD8+ T cells were transferred at the time of infection with Chlamydia. However, when the transfer was delayed for 2 weeks or longer after the chlamydial infection, naïve CD8+ T cells no longer promoted hydrosalpinx. Nevertheless, Chlamydia-immunized CD8+ T cells still promoted significant hydrosalpinx in the recipient OT1 mice even when the transfer was delayed for 3 weeks. Thus, CD8+ T cells must be primed within 2 weeks after chlamydial infection to be pathogenic but once primed, they can promote hydrosalpinx for >3 weeks. However, Chlamydia-primed CD4+ T cells failed to promote chlamydial induction of pathology in OT1 mice. This study has optimized an OT1 mouse-based model for revealing the pathogenic mechanisms of Chlamydia-specific CD8+ T cells.
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Gastrointestinal Chlamydia-induced CD8 + T cells promote chlamydial pathogenicity in the female upper genital tract. Infect Immun 2021; 89:e0020521. [PMID: 34227838 DOI: 10.1128/iai.00205-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chlamydia is known to both ascend to the upper genital tract and spread to the gastrointestinal tract following intravaginal inoculation. The gastrointestinal Chlamydia was recently reported to promote chlamydial pathogenicity in the genital tract since mice intravaginally inoculated with an attenuated Chlamydia, which alone failed to develop pathology in the genital tract, were restored to develop hydrosalpinx by intragastric co-inoculation with wild type Chlamydia. Gastrointestinal Chlamydia promoted hydrosalpinx via an indirect mechanism since Chlamydia in the gut did not directly spread to the genital tract lumen. In the current study, we further investigated the role of CD8+ T cells in the promotion of hydrosalpinx by gastrointestinal Chlamydia. First, we confirmed that intragastric co-inoculation with wild type Chlamydia promoted hydrosalpinx in mice that were inoculated with an attenuated Chlamydia in the genital tract one week earlier. Second, the promotion of hydrosalpinx by intragastrically co-inoculated Chlamydia was blocked by depleting CD8+ T cells. Third, adoptive transfer of the gastrointestinal Chlamydia-induced CD8+ T cells was sufficient for promoting hydrosalpinx in mice that were intravaginally inoculated with an attenuated Chlamydia. These observations have demonstrated that CD8+ T cells induced by gastrointestinal Chlamydia are both necessary and sufficient for promoting hydrosalpinx in the genital tract. The study has laid a foundation for further revealing the mechanisms by which Chlamydia-induced T lymphocyte responses (as a 2nd hit) promote hydrosalpinx in mice with genital Chlamydia-triggered tubal injury (as a 1st hit), a continuing effort in testing the two-hit hypothesis as a chlamydial pathogenic mechanism.
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Dockterman J, Coers J. Immunopathogenesis of genital Chlamydia infection: insights from mouse models. Pathog Dis 2021; 79:6128668. [PMID: 33538819 DOI: 10.1093/femspd/ftab012] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 02/02/2021] [Indexed: 12/13/2022] Open
Abstract
Chlamydiae are pathogenic intracellular bacteria that cause a wide variety of diseases throughout the globe, affecting the eye, lung, coronary arteries and female genital tract. Rather than by direct cellular toxicity, Chlamydia infection generally causes pathology by inducing fibrosis and scarring that is largely mediated by host inflammation. While a robust immune response is required for clearance of the infection, certain elements of that immune response may also damage infected tissue, leading to, in the case of female genital infection, disease sequelae such as pelvic inflammatory disease, infertility and ectopic pregnancy. It has become increasingly clear that the components of the immune system that destroy bacteria and those that cause pathology only partially overlap. In the ongoing quest for a vaccine that prevents Chlamydia-induced disease, it is important to target mechanisms that can achieve protective immunity while preventing mechanisms that damage tissue. This review focuses on mouse models of genital Chlamydia infection and synthesizes recent studies to generate a comprehensive model for immunity in the murine female genital tract, clarifying the respective contributions of various branches of innate and adaptive immunity to both host protection and pathogenic genital scarring.
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Affiliation(s)
- Jacob Dockterman
- Department of Immunology, Duke University Medical Center, Durham, NC 22710, USA
| | - Jörn Coers
- Department of Immunology, Duke University Medical Center, Durham, NC 22710, USA.,Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 22710, USA
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Effects of Immunomodulatory Drug Fingolimod (FTY720) on Chlamydia Dissemination and Pathogenesis. Infect Immun 2020; 88:IAI.00281-20. [PMID: 32868341 DOI: 10.1128/iai.00281-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/24/2020] [Indexed: 12/21/2022] Open
Abstract
Fingolimod (FTY720), an FDA-approved immunomodulatory drug for treating multiple sclerosis, is an agonist of sphingosine-1-phosphate receptor (S1PR), which has been used as a research tool for inhibiting immune cell trafficking. FTY720 was recently reported to inhibit Chlamydia dissemination. Since genital Chlamydia spreading to the gastrointestinal tract correlated with its pathogenicity in the upper genital tract, we evaluated the effect of FTY720 on chlamydial pathogenicity in the current study. Following an intravaginal inoculation, live chlamydial organisms were detected in mouse rectal swabs. FTY720 treatment significantly delayed live organism shedding in the rectal swabs. However, FTY720 failed to block chlamydial spreading to the gastrointestinal tract. The live chlamydial organisms recovered from rectal swabs reached similar levels between mice with or without FTY720 treatment by day 42 in C57BL/6J and day 28 in CBA/J mice, respectively. Thus, genital Chlamydia is able to launch a 2nd wave of spreading via an FTY720-resistant pathway after the 1st wave of spreading is inhibited by FTY720. As a result, all mice developed significant hydrosalpinx. The FTY720-resistant spreading led to stable colonization of chlamydial organisms in the colon. Consistently, FTY720 did not alter the colonization of intracolonically inoculated Chlamydia Thus, we have demonstrated that, following a delay in chlamydial spreading caused by FTY720, genital Chlamydia is able to both spread to the gastrointestinal tract via an FTY720-resistant pathway and maintain its pathogenicity in the upper genital tract. Further characterization of the FTY720-resistant pathway(s) explored by Chlamydia for spreading to the gastrointestinal tract may promote our understanding of Chlamydia pathogenic mechanisms.
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Xie L, He C, Chen J, Tang L, Zhou Z, Zhong G. Suppression of Chlamydial Pathogenicity by Nonspecific CD8 + T Lymphocytes. Infect Immun 2020; 88:e00315-20. [PMID: 32747602 PMCID: PMC7504968 DOI: 10.1128/iai.00315-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/27/2020] [Indexed: 12/13/2022] Open
Abstract
Chlamydia trachomatis, a leading infectious cause of tubal infertility, induces upper genital tract pathology, such as hydrosalpinx, which can be modeled with Chlamydia muridarum infection in mice. Following C. muridarum inoculation, wild-type mice develop robust hydrosalpinx, but OT1 mice fail to do so because their T cell receptors are engineered to recognize a single ovalbumin epitope (OVA457-462). These observations have demonstrated a critical role of Chlamydia-specific T cells in chlamydial pathogenicity. In the current study, we have also found that OT1 mice can actively inhibit chlamydial pathogenicity. First, depletion of CD8+ T cells from OT1 mice led to the induction of significant hydrosalpinx by Chlamydia, indicating that CD8+ T cells are necessary to inhibit chlamydial pathogenicity. Second, adoptive transfer of CD8+ T cells from OT1 mice to CD8 knockout mice significantly reduced chlamydial induction of hydrosalpinx, demonstrating that OT1 CD8+ T cells are sufficient for attenuating chlamydial pathogenicity in CD8 knockout mice. Finally, CD8+ T cells from OT1 mice also significantly inhibited hydrosalpinx development in wild-type mice following an intravaginal inoculation with Chlamydia Since T cells in OT1 mice are engineered to recognize only the OVA457-462 epitope, the above observations have demonstrated a chlamydial antigen-independent immune mechanism for regulating chlamydial pathogenicity. Further characterization of this mechanism may provide information for developing strategies to reduce infertility-causing pathology induced by infections.
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Affiliation(s)
- Lingxiang Xie
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
- The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Conghui He
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Jianlin Chen
- The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Lingli Tang
- The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Zhiguang Zhou
- The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Guangming Zhong
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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Gastrointestinal Coinfection Promotes Chlamydial Pathogenicity in the Genital Tract. Infect Immun 2020; 88:IAI.00905-19. [PMID: 31988173 DOI: 10.1128/iai.00905-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 01/21/2020] [Indexed: 01/11/2023] Open
Abstract
Sexually transmitted Chlamydia, which can cause fibrotic pathology in women's genital tracts, is also frequently detected in the gastrointestinal tract. However, the medical significance of the gastrointestinal Chlamydia remains unclear. A murine Chlamydia readily spreads from the mouse genital tract to the gastrointestinal tract while inducing oviduct fibrotic blockage or hydrosalpinx. We previously proposed a two-hit model in which the mouse gastrointestinal Chlamydia might induce the second hit to promote genital tract pathology, and we are now providing experimental evidence for testing the hypothesis. First, chlamydial mutants that are attenuated in inducing hydrosalpinx in the genital tract also reduce their colonization in the gastrointestinal tract, leading to a better correlation of chlamydial induction of hydrosalpinx with chlamydial colonization in the gastrointestinal tract than in the genital tract. Second, intragastric coinoculation with a wild-type Chlamydia rescued an attenuated Chlamydia mutant to induce hydrosalpinx, while the chlamydial mutant infection in the genital tract alone was unable to induce any significant hydrosalpinx. Finally, the coinoculated gastrointestinal Chlamydia failed to directly spread to the genital tract lumen, suggesting that gastrointestinal Chlamydia may promote genital pathology via an indirect mechanism. Thus, we have demonstrated a significant role of gastrointestinal Chlamydia in promoting pathology in the genital tract possibly via an indirect mechanism. This study provides a novel direction/dimension for further investigating chlamydial pathogenic mechanisms.
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Chlamydia and Its Many Ways of Escaping the Host Immune System. J Pathog 2019; 2019:8604958. [PMID: 31467721 PMCID: PMC6699355 DOI: 10.1155/2019/8604958] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/02/2019] [Indexed: 12/18/2022] Open
Abstract
The increasing number of new cases of Chlamydia infection worldwide may be attributed to the pathogen's ability to evade various host immune responses. Summarized here are means of evasion utilized by Chlamydia enabling survival in a hostile host environment. The pathogen's persistence involves a myriad of molecular interactions manifested in a variety of ways, e.g., formation of membranous intracytoplasmic inclusions and cytokine-induced amino acid synthesis, paralysis of phagocytic neutrophils, evasion of phagocytosis, inhibition of host cell apoptosis, suppression of antigen presentation, and induced expression of a check point inhibitor of programmed host cell death. Future studies could focus on the targeting of these molecules associated with immune evasion, thus limiting the spread and tissue damage caused by this pathogen.
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ZHang T, Li H, Lan X, ZHang CH, Yang ZH, Cao W, Fen N, Liu Y, Yan Y, Yasheng A, Ma X. The bioinformatics analyses reveal novel antigen epitopes in major outer membrane protein of Chlamydia trachomatis. Indian J Med Microbiol 2018; 35:522-528. [PMID: 29405144 DOI: 10.4103/ijmm.ijmm_17_251] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
PURPOSE The aim of this study was to predict the T-cell and B-cell epitopes in major outer membrane protein (MOMP) of Chlamydia trachomatis (CT) by using online software and also to analyse the secondary structure of MOMP through bioinformatics tools. MATERIALS AND METHODS The predictions of secondary structure of MOMP protein were carried out using SOPMA software, and the prediction of B-cell epitopes in MOMP protein was carried out using IEDB and LEPS software, while the T-cell epitopes were predicted by the software of IEBD and SYFPEITHI. The predictions from the software were combined with MOMP protein characteristics, including surface features, hydrophilicity, flexibility, accessibility and plasticity, to analyse the common epitope areas' response by T-cells and B-cells. RESULTS In the secondary structure of CT MOMP, the alpha-helices accounted for 41.62% of total amino acid, while the beta sheets and random coil accounted for 19.80% and 32.49%, respectively. Predictions combined with MOMP protein surface features, hydrophilicity, flexibility, accessibility and plasticity were further characterised, and three high-score B-cell epitope areas were found as located in 24-31, 307-311 and 318-327 amino acids of MOMP protein, respectively; in the meanwhile, three high-score T-cell epitope areas were found in 234-236, 323-329 and 338-343 amino acids of MOMP using major histocompatibility complex (MHC) class I HLA-A 0201 restrictive T-cell epitope analyser. CONCLUSION We established the methods by using the biological information network technologies for looking the T-cell antigen epitopes and B-cell antigen epitopes in MOMP of CT, and three novel T-cell epitopes as well as three novel B-cell epitopes were identified in the current study. It provides important information for further studying the antigenicity of CT MOMP protein and also provides useful information for developing highly efficient subunit vaccines for CT.
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Affiliation(s)
- Tao ZHang
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research (2010DS890294) and Xinjiang Key Laboratory of Echinococcosis, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - Huijun Li
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research (2010DS890294) and Xinjiang Key Laboratory of Echinococcosis, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - Xi Lan
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research (2010DS890294) and Xinjiang Key Laboratory of Echinococcosis, First Affiliated Hospital of Xinjiang Medical University; Shenzhen Hospital of Southern Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - CHuntao ZHang
- College of Basic Medicine of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - ZHangsheng Yang
- Department of Microbiology and Immunologya and Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Wenyan Cao
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research (2010DS890294) and Xinjiang Key Laboratory of Echinococcosis, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - Ning Fen
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research (2010DS890294) and Xinjiang Key Laboratory of Echinococcosis, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - Yumei Liu
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research (2010DS890294) and Xinjiang Key Laboratory of Echinococcosis, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - Yi Yan
- College of Basic Medicine of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - Amanguli Yasheng
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research (2010DS890294) and Xinjiang Key Laboratory of Echinococcosis, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
| | - Xiumin Ma
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research (2010DS890294) and Xinjiang Key Laboratory of Echinococcosis, First Affiliated Hospital of Xinjiang Medical University; College of Basic Medicine of Xinjiang Medical University, Urumqi, Xinjiang 830011, P.R. China
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Chlamydial plasmid-encoded virulence factor Pgp3 interacts with human cathelicidin peptide LL-37 to modulate immune response. Microbes Infect 2018; 21:50-55. [PMID: 29959096 DOI: 10.1016/j.micinf.2018.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/17/2018] [Accepted: 06/19/2018] [Indexed: 11/23/2022]
Abstract
We have previously reported that Chlamydia trachomatis plasmid-encoded Pgp3 is able to neutralize anti-chlamydial activity of human cathelicidin peptide LL-37 by binding to and forming stable complex with LL-37. Besides its microbicidal activity, LL-37 also modulates immune response, including inducing cytokine/chemokine production in fibroblast/epithelial cells and recruitment of inflammatory cells. We now report that LL-37 was significantly induced in the genital tracts of women diagnosed positive for C. trachomatis. Both the LL-37-stimulated IL-6/8 production in human endometrial epithelial cells and the LL-37-induced neutrophil chemotaxis were blocked by Pgp3. Interestingly, although Pgp3 itself alone could not induce cytokines in epithelial cell cells, it did so in neutrophils. Importantly, the Pgp3 proinflammatory activity in neutrophils was significantly enhanced by forming complex with LL-37 although LL-37 alone failed to induce cytokine production in neutrophils. Thus, we have demonstrated that Pgp3 can modulate the proinflammatory activities of LL-37 on epithelial cells by forming stable complex with LL-37 but the Pgp3's own proinflammatory activity on myeloid cells is enhanced by forming the same complex. We hypothesize that Chlamydia may use Pgp3 to both block detrimental inflammation for improving its own fitness in the genital tract epithelial tissue and activate myeloid cell-mediated inflammation for potentially promoting spreading between the hosts, the latter of which may inevitably contribute to the development of inflammatory sequelae such as tubal fibrosis.
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14
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Zhong G. Chlamydia Spreading from the Genital Tract to the Gastrointestinal Tract - A Two-Hit Hypothesis. Trends Microbiol 2017; 26:611-623. [PMID: 29289422 DOI: 10.1016/j.tim.2017.12.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/21/2017] [Accepted: 12/06/2017] [Indexed: 12/18/2022]
Abstract
Chlamydia trachomatis, a leading bacterial cause of sexually transmitted infection-induced infertility, is frequently detected in the gastrointestinal tract. Chlamydia muridarum, a model pathogen for investigating C. trachomatis pathogenesis, readily spreads from the mouse genital tract to the gastrointestinal tract, establishing long-lasting colonization. C. muridarum mutants, despite their ability to activate acute oviduct inflammation, are attenuated in inducing tubal fibrosis and are no longer able to colonize the gastrointestinal tract, suggesting that the spread of C. muridarum to the gastrointestinal tract may contribute to its pathogenicity in the upper genital tract. However, gastrointestinal C. muridarum cannot directly autoinoculate the genital tract. Both antigen-specific CD8+ T cells and profibrotic cytokines, such as TNFα and IL-13, are essential for C. muridarum to induce tubal fibrosis; this may be induced by the gastrointestinal C. muridarum, as a second hit, to transmucosally convert tubal repairing - initiated by C. muridarum infection of tubal epithelial cells (serving as the first hit) - into pathogenic fibrosis. Testing the two-hit mouse model should both add new knowledge to the growing list of mechanisms by which gastrointestinal microbes contribute to pathologies in extragastrointestinal tissues and provide information for investigating the potential role of gastrointestinal C. trachomatis in human chlamydial pathogenesis.
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Affiliation(s)
- Guangming Zhong
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health, Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
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15
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The Genital Tract Virulence Factor pGP3 Is Essential for Chlamydia muridarum Colonization in the Gastrointestinal Tract. Infect Immun 2017; 86:IAI.00429-17. [PMID: 29038127 DOI: 10.1128/iai.00429-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/04/2017] [Indexed: 02/06/2023] Open
Abstract
The cryptic plasmid is essential for Chlamydia muridarum dissemination from the genital tract to the gastrointestinal (GI) tract. Following intravaginal inoculation, a C. muridarum strain deficient in plasmid-encoded pGP3 or pGP4 but not pGP5, pGP7, or pGP8 failed to spread to the mouse gastrointestinal tract, although mice infected with these strains developed productive genital tract infections. pGP3- or pGP4-deficient strains also failed to colonize the gastrointestinal tract when delivered intragastrically. pGP4 regulates pGP3, while pGP3 does not affect pGP4 expression, indicating that pGP3 is critical for C. muridarum colonization of the gastrointestinal tract. Mutants deficient in GlgA, a chromosome-encoded protein regulated by pGP4, also consistently colonized the mouse gastrointestinal tract. Interestingly, C. muridarum colonization of the gastrointestinal tract positively correlated with pathogenicity in the upper genital tract. pGP3-deficient C. muridarum strains did not induce hydrosalpinx or spread to the GI tract even when delivered to the oviduct by intrabursal inoculation. Thus, the current study not only has revealed that pGP3 is a novel chlamydial colonization factor in the gastrointestinal tract but also has laid a foundation for investigating the significance of gastrointestinal Chlamydia.
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16
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Sun X, Tian Q, Wang L, Xue M, Zhong G. IL-6-mediated signaling pathways limit Chlamydia muridarum infection and exacerbate its pathogenicity in the mouse genital tract. Microbes Infect 2017; 19:536-545. [PMID: 28864426 PMCID: PMC6034988 DOI: 10.1016/j.micinf.2017.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 07/29/2017] [Accepted: 08/18/2017] [Indexed: 12/19/2022]
Abstract
Chlamydia muridarum induction of mouse hydrosalpinx, depending on both tubal infection and inflammation, has been used for investigating Chlamydia trachomatis pathogenesis. We now report that IL-6 both inhibits C. muridarum infection and exacerbates pathogenicity in the mouse genital tract. When intravaginally inoculated with a high dose of C. muridarum, IL-6-deficient mice developed more extensive genital tract infection with severe hydrosalpinx, suggesting that IL-6 is required for controlling the high dose infection but not essential for C. muridarum-induced pathology. However, at a low dose, IL-6-deficient mice still developed more extensive infection in the genital tract but no longer with significant pathology, suggesting that IL-6 is required for both controlling the low dose infection and exacerbating the low dose infection-induced pathology. The lack of hydrosalpinx in IL-6-deficient mice correlated with significantly reduced inflammatory infiltration in the oviduct tissue and decreased spleen CD4+ and CD8+ T cells that produce TNFα. Thus, IL-6-dependent pathways are important for both limiting chlamydial colonization in the genital tract mucosal tissues regardless of the infection doses and exacerbating chlamydial pathogenicity in the upper genital tract when IL-6-independent pathogenic mechanisms are not yet activated with a low infection dose.
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Affiliation(s)
- Xin Sun
- Department of Obstetrics and Gynecology, 3rd Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China; Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Qi Tian
- Department of Obstetrics and Gynecology, 3rd Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China; Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Luying Wang
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Min Xue
- Department of Obstetrics and Gynecology, 3rd Xiangya Hospital, Central South University, Changsha, Hunan 410008, PR China.
| | - Guangming Zhong
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
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17
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Neutrophils Are Central to Antibody-Mediated Protection against Genital Chlamydia. Infect Immun 2017; 85:IAI.00409-17. [PMID: 28739831 PMCID: PMC5607418 DOI: 10.1128/iai.00409-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022] Open
Abstract
Determining the effector populations involved in humoral protection against genital chlamydia infection is crucial to development of an effective chlamydial vaccine. Antibody has been implicated in protection studies in multiple animal models, and we previously showed that the passive transfer of immune serum alone does not confer immunity in the mouse. Using the Chlamydia muridarum model of genital infection, we demonstrate a protective role for both Chlamydia-specific immunoglobulin G (IgG) and polymorphonuclear neutrophils and show the importance of an antibody/effector cell interaction in mediating humoral immunity. While neutrophils were found to contribute significantly to antibody-mediated protection in vivo, natural killer (NK) cells were dispensable for protective immunity. Furthermore, gamma interferon (IFN-γ)-stimulated primary peritoneal neutrophils (PPNs) killed chlamydiae in vitro in an antibody-dependent manner. The results from this study support the view that an IFN-γ-activated effector cell population cooperates with antibody to protect against genital chlamydia and establish neutrophils as a key effector cell in this response.
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18
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Li LX, Labuda JC, Imai DM, Griffey SM, McSorley SJ. CCR7 Deficiency Allows Accelerated Clearance of Chlamydia from the Female Reproductive Tract. THE JOURNAL OF IMMUNOLOGY 2017; 199:2547-2554. [PMID: 28801359 DOI: 10.4049/jimmunol.1601314] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 07/21/2017] [Indexed: 12/24/2022]
Abstract
Immune mechanisms responsible for pathogen clearance from the female reproductive tract (FRT) are incompletely defined; in particular, the contribution of lymphocyte trafficking to this process is unclear. CCR7-deficient mice have profoundly altered lymphocyte recirculation and display ectopic formation of lymphocyte aggregates within mucosal nonlymphoid tissues, including the FRT. In this study, we investigated how altered lymphocyte distribution in CCR7-deficient mice would affect host responses to Chlamydia muridarum within the reproductive tract. As expected, CCR7-deficient mice exhibited reduced lymphocyte trafficking to lymph nodes and a corresponding increase in T cell populations within the FRT. After intravaginal infection with Chlamydia, CCR7-deficient mice displayed markedly reduced Ag-specific CD4 T cell responses within the local draining iliac lymph nodes, yet robust Th1 and Th17 responses were prominent in the FRT. In addition, Chlamydia-specific Ab responses were dysregulated in CCR7-deficient mice, displaying an unexpected increase in the systemic IgA responses. Importantly, prominent mucosal immune responses in CCR7-deficient mice increased the efficiency of bacteria clearance from the FRT while reducing tissue-associated inflammation and pathology. Thus, increased numbers of lymphocytes within the FRT result in pathogen clearance with reduced immune-mediated pathology.
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Affiliation(s)
- Lin-Xi Li
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205;
| | - Jasmine C Labuda
- Center for Comparative Medicine, Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616; and
| | - Denise M Imai
- Comparative Pathology Laboratory, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
| | - Stephen M Griffey
- Comparative Pathology Laboratory, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616
| | - Stephen J McSorley
- Center for Comparative Medicine, Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616; and
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19
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Chlamydia muridarum with Mutations in Chromosomal Genes tc0237 and/or tc0668 Is Deficient in Colonizing the Mouse Gastrointestinal Tract. Infect Immun 2017; 85:IAI.00321-17. [PMID: 28584162 PMCID: PMC5520443 DOI: 10.1128/iai.00321-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/26/2017] [Indexed: 12/20/2022] Open
Abstract
Chlamydiae colonize the gastrointestinal tracts of both animals and humans. However, their medical significance remains unknown. We have previously shown that wild-type Chlamydia muridarum spreads to and establishes stable colonization of the gastrointestinal tract following intravaginal inoculation. In the present study, we found that C. muridarum with mutations in chromosomal genes tc0237 and/or tc0668 was defective in spreading to the mouse gastrointestinal tract, which correlated with its attenuated pathogenicity in the upper genital tract. This correlation was more consistent than that of chlamydial pathogenicity with ascending infection in the genital tract, since attenuated C. muridarum spread significantly less to the gastrointestinal tract but maintained robust ascending infection of the upper genital tract. Transcervical inoculation further confirmed the correlation between C. muridarum spreading to the gastrointestinal tract and its pathogenicity in the upper genital tract. Finally, defective spreading of C. muridarum mutants was due to their inability to colonize the gastrointestinal tract since intragastric inoculation did not rescue the mutants' colonization. Thus, promoting C. muridarum colonization of the gastrointestinal tract may represent a primary function of the TC0237 and TC0668 proteins. Correlation of chlamydial colonization of the gastrointestinal tract with chlamydial pathogenicity in the upper genital tract suggests a potential role for gastrointestinal chlamydiae in genital tract pathogenicity.
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20
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Shao L, Melero J, Zhang N, Arulanandam B, Baseman J, Liu Q, Zhong G. The cryptic plasmid is more important for Chlamydia muridarum to colonize the mouse gastrointestinal tract than to infect the genital tract. PLoS One 2017; 12:e0177691. [PMID: 28542376 PMCID: PMC5444651 DOI: 10.1371/journal.pone.0177691] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 05/02/2017] [Indexed: 02/07/2023] Open
Abstract
Chlamydia has been detected in the gastrointestinal tracts of both animals and humans. However, the mechanism by which Chlamydia colonizes the gut remains unclear. Chlamydia muridarum is known to spread from the genital to the gastrointestinal tracts hematogenously. The C. muridarum plasmid is a key pathogenic determinant in the mouse upper genital tract although plasmid-deficient C. muridarum is still able to colonize the upper genital tract. We now report that plasmid-deficient C. muridarum exhibits significantly delayed/reduced spreading from the mouse genital to the gastrointestinal tracts. C. muridarum with or without plasmid maintained similar levels in the mouse circulatory system following intravenous inoculation but the hematogenous plasmid-deficient C. muridarum was significantly less efficient in colonizing the gastrointestinal tract. Consistently, plasmid-deficient C. muridarum failed to restore normal colonization in the gastrointestinal tract even after intragastric inoculation at a high dose. Thus, we have demonstrated a plasmid-dependent colonization of C. muridarum in the gastrointestinal tract, supporting the concept that C. muridarum may have acquired the plasmid for adaptation to the mouse gastrointestinal tract during oral-fecal transmission. Since the plasmid is more important for C. muridarum to colonize the gastrointestinal tract than to infect the genital tract, the current study has laid a foundation for further defining the host pathways targeted by the plasmid-encoded or -regulated chlamydial effectors.
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Affiliation(s)
- Lili Shao
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Dermatovenereology, Tianjin Medical University General Hospital, Tianjin, China
| | - Jose Melero
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Nu Zhang
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Bernard Arulanandam
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Joel Baseman
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Quanzhong Liu
- Department of Dermatovenereology, Tianjin Medical University General Hospital, Tianjin, China
| | - Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
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21
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Update on Chlamydia trachomatis Vaccinology. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00543-16. [PMID: 28228394 DOI: 10.1128/cvi.00543-16] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Attempts to produce a vaccine to protect against Chlamydia trachomatis-induced trachoma were initiated more than 100 years ago and continued for several decades. Using whole organisms, protective responses were obtained. However, upon exposure to C. trachomatis, disease exacerbation developed in some immunized individuals, precluding the implementation of the vaccine. Evidence of the role of C. trachomatis as a sexually transmitted pathogen started to emerge in the 1960s, and it soon became evident that it can cause acute infections and long-term sequelae in women, men, and newborns. The main focus of this minireview is to summarize recent findings and discuss formulations, including antigens, adjuvants, routes, and delivery systems for immunization, primarily explored in the female mouse model, with the goal of implementing a vaccine against C. trachomatis genital infections.
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22
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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: 72] [Impact Index Per Article: 9.0] [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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23
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Yang Z, Tang L, Shao L, Zhang Y, Zhang T, Schenken R, Valdivia R, Zhong G. The Chlamydia-Secreted Protease CPAF Promotes Chlamydial Survival in the Mouse Lower Genital Tract. Infect Immun 2016; 84:2697-702. [PMID: 27382018 PMCID: PMC4995919 DOI: 10.1128/iai.00280-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 06/30/2016] [Indexed: 12/16/2022] Open
Abstract
Despite the extensive in vitro characterization of CPAF (chlamydial protease/proteasome-like activity factor), its role in chlamydial infection and pathogenesis remains unclear. We now report that a Chlamydia trachomatis strain deficient in expression of CPAF (L2-17) is no longer able to establish a successful infection in the mouse lower genital tract following an intravaginal inoculation. The L2-17 organisms were cleared from the mouse lower genital tract within a few days, while a CPAF-sufficient C. trachomatis strain (L2-5) survived in the lower genital tract for more than 3 weeks. However, both the L2-17 and L2-5 organisms maintained robust infection courses that lasted up to 4 weeks when they were directly delivered into the mouse upper genital tract. The CPAF-dependent chlamydial survival in the lower genital tract was confirmed in multiple strains of mice. Thus, we have demonstrated a critical role of CPAF in promoting C. trachomatis survival in the mouse lower genital tracts. It will be interesting to further investigate the mechanisms of the CPAF-dependent chlamydial pathogenicity.
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Affiliation(s)
- Zhangsheng Yang
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Lingli Tang
- Department of Clinic Diagnosis, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lili Shao
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Yuyang Zhang
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Tianyuan Zhang
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Robert Schenken
- Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Raphael Valdivia
- Duke Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Guangming Zhong
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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24
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Hines CDG, Wang S, Meng X, Skinner JM, Heinrichs JH, Smith JG, Boddicker MA. MRI as a Novel In Vivo Approach for Assessing Structural Changes of Chlamydia Pathology in a Mouse Model. PLoS One 2016; 11:e0160055. [PMID: 27467585 PMCID: PMC4965011 DOI: 10.1371/journal.pone.0160055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 07/13/2016] [Indexed: 12/18/2022] Open
Abstract
Chlamydia trachomatis is among the most prevalent of sexually transmitted diseases. While Chlamydia infection is a reportable event and screening has increased over time, enhanced surveillance has not resulted in a reduction in the rate of infections, and Chlamydia infections frequently recur. The development of a preventative vaccine for Chlamydia may be the only effective approach for reducing infection and the frequency of pathological outcomes. Current vaccine research efforts involve time consuming and/or invasive approaches for assessment of disease state, and MRI presents a clinically translatable method for assessing infection and related pathology both quickly and non-invasively. Longitudinal T2-weighted MRI was performed over 63 days on both control or Chlamydia muridarum challenged mice, either with or without elementary body (EB) immunization, and gross necropsy was performed on day 65. A scoring system was developed to assess the number of regions affected by Chlamydia pathology and was used to document pathology over time and at necropsy. The scoring system documented increasing incidence of pathology in the unimmunized and challenged mice (significantly greater compared to the control and EB immunized-challenged groups) by 21 days post-challenge. No differences between the unchallenged and EB immunized-challenged mice were observed. MRI scores at Day 63 were consistently higher than gross necropsy scores at Day 65, although two of the three groups of mice showed no significant differences between the two techniques. In this work we describe the application of MRI in mice for the potential evaluation of disease pathology and sequelae caused by C. muridarum infection and this technique’s potential for evaluation of vaccines for Chlamydia.
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Affiliation(s)
- Catherine D G Hines
- Department of Translational Imaging Biomarkers, MRL (West Point, PA), Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Shubing Wang
- Department of Biometrics Research, MRL (Rahway, NJ), Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Xiangjun Meng
- Department of Translational Imaging Biomarkers, MRL (West Point, PA), Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Julie M Skinner
- Department of Vaccines Early Discovery, MRL (West Point, PA), Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Jon H Heinrichs
- Global Project Leadership, Sanofi Pasteur, Swiftwater, Pennsylvania, United States of America
| | - Jeffrey G Smith
- Pharmaceutical Sciences Analytical Research & Development, Pfizer, Andover, Massachusetts, United States of America
| | - Melissa A Boddicker
- Department of Vaccines Early Discovery, MRL (West Point, PA), Merck & Co., Inc., Kenilworth, New Jersey, United States of America
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25
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Intravenous Inoculation with Chlamydia muridarum Leads to a Long-Lasting Infection Restricted to the Gastrointestinal Tract. Infect Immun 2016; 84:2382-2388. [PMID: 27271744 DOI: 10.1128/iai.00432-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/01/2016] [Indexed: 12/16/2022] Open
Abstract
Chlamydia has been detected in the gastrointestinal tracts of both animals and humans. However, it remains unclear whether the chlamydial organisms can be introduced into the gastrointestinal tract via pathways independent of the oral and anal routes. We have recently shown that Chlamydia muridarum spreads from the genital tract to the gastrointestinal tract potentially via the circulatory system. To test whether hematogenous C. muridarum can spread to and establish a long-lasting colonization in the mouse gastrointestinal tract, we inoculated mice intravenously with a luciferase-expressing C. muridarum strain and monitored its distribution. After tail vein inoculation, most luciferase-generated bioluminescence signals were detected in the mouse abdominal area throughout the experiment. The ex vivo imaging revealed that the abdominal signals came from the gastrointestinal tract tissues. Simultaneous monitoring of chlamydial organisms in individual organs or tissues revealed an initial stage of systemic spreading followed by a long-lasting infection in the gastrointestinal tract. A retro-orbital vein inoculation of the C. muridarum organisms at a lower dose in a different mouse strain also led to colonization of the gastrointestinal tract. We have demonstrated that intravenous C. muridarum inoculation can result in colonization of the gastrointestinal tract, suggesting that the chlamydial organisms may use the sexual behavior-independent circulation pathway to infect the gastrointestinal tract.
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26
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Wang L, Zhang Q, Zhang T, Zhang Y, Zhu C, Sun X, Zhang N, Xue M, Zhong G. The Chlamydia muridarum Organisms Fail to Auto-Inoculate the Mouse Genital Tract after Colonization in the Gastrointestinal Tract for 70 days. PLoS One 2016; 11:e0155880. [PMID: 27192556 PMCID: PMC4871562 DOI: 10.1371/journal.pone.0155880] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/05/2016] [Indexed: 11/18/2022] Open
Abstract
Chlamydia muridarum is known to colonize in the gastrointestinal tract for long periods of time, which has been hypothesized to serve as a reservoir for spreading to the genital tract. To test this hypothesis, a luciferase-expressing C. muridarum was used to establish a long-lasting infection in the mouse gastrointestinal tract following either intragastric or intrarectal inoculations. In vivo imaging revealed significant bioluminescent signals mainly in the mouse abdominal area throughout the experiments. Ex vivo imaging localized the signals to the mouse gastrointestinal tract, which was confirmed by monitoring the C. muridarum organisms in the mouse organs/tissues. Despite the long-lasting colonization in the gastrointestinal tract and active shedding of infectious organisms in the rectal swabs, the organisms did not cause any significant infection or pathology in the genital tract throughout the experiments, which was reproduced in multiple strains of mice and with an increased inoculation dose to the gastrointestinal tract. The above observations have demonstrated that the long-lasting C. muridarum organisms from the gastrointestinal tract are inefficient in auto-inoculating the genital tract, suggesting that the gastrointestinal tract Chlamydia may utilize an indirect mechanism to affect its pathogenicity in the genital tract.
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Affiliation(s)
- Luying Wang
- The 3 Xiangya Hospital, Central South University, Changsha, Hunan 400000, P. R. China
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Texas, United States of America
| | - Qi Zhang
- The 3 Xiangya Hospital, Central South University, Changsha, Hunan 400000, P. R. China
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Texas, United States of America
| | - Tianyuan Zhang
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Texas, United States of America
| | - Yuyang Zhang
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Texas, United States of America
| | - Cuiming Zhu
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Texas, United States of America
| | - Xin Sun
- The 3 Xiangya Hospital, Central South University, Changsha, Hunan 400000, P. R. China
| | - Nu Zhang
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Texas, United States of America
| | - Min Xue
- The 3 Xiangya Hospital, Central South University, Changsha, Hunan 400000, P. R. China
| | - Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, Texas, United States of America
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Poston TB, Darville T. Chlamydia trachomatis: Protective Adaptive Responses and Prospects for a Vaccine. Curr Top Microbiol Immunol 2016; 412:217-237. [PMID: 27033698 DOI: 10.1007/82_2016_6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Chlamydia trachomatis is the most common cause of sexually transmitted bacterial infection globally. These infections translate to a significant public health burden, particularly women's healthcare costs due to serious disease sequelae such as pelvic inflammatory disease (PID), tubal factor infertility, chronic pelvic pain, and ectopic pregnancy. There is no evidence that natural immunity can provide complete, long-term protection necessary to prevent chronic pathology, making human vaccine development critical. Vaccine design will require careful consideration of protective versus pathological host-response mechanisms in concert with elucidation of optimal antigens and adjuvants. Evidence suggests that a Th1 response, facilitated by IFN-γ-producing CD4 T cells, will be instrumental in generating long-term, sterilizing immunity. Although the role of antibodies is not completely understood, they have exhibited a protective effect by enhancing chlamydial clearance. Future work will require investigation of broadly neutralizing antibodies and antibody-augmented cellular immunity to successfully design a vaccine that potently elicits both arms of the immune response. Sterilizing immunity is the ultimate goal. However, vaccine-induced partial immunity that prevents upper genital tract infection and inflammation would be cost-effective compared to current screening and treatment strategies. In this chapter, we examine evidence from animal and human studies demonstrating protective adaptive immune responses to Chlamydia and discuss future challenges and prospects for vaccine development.
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Affiliation(s)
- Taylor B Poston
- Department of Pediatrics, University of North Carolina, Chapel Hill, NC, USA
| | - Toni Darville
- Department of Pediatrics, University of North Carolina, Chapel Hill, NC, USA.
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Dai J, Tang L, Chen J, Yu P, Chen Z, Zhong G. The p47phox deficiency significantly attenuates the pathogenicity of Chlamydia muridarum in the mouse oviduct but not uterine tissues. Microbes Infect 2015; 18:190-8. [PMID: 26645958 DOI: 10.1016/j.micinf.2015.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/07/2015] [Accepted: 11/12/2015] [Indexed: 12/15/2022]
Abstract
The Chlamydia muridarum induction of the upper genital tract pathology in mice has been used to investigate the mechanisms of chlamydial pathogenesis. We report that the NCF1 (neutrophil cytosolic factor1)-encoded p47phox (phagocyte oxidase), an essential subunit of nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase, contributes significantly to C. muridarum induction of hydrosalpinx. Mice lacking p47phox (p47phox-deficient) were no longer able to develop significant hydrosalpinx following an intravaginal infection with C. muridarum. However, there was no significant difference in uterine horn dilation (as a result of the endometrial glandular duct dilation) between the p47phox-deficient and -sufficient mice. Thus, the role of NADPH oxidase in chlamydial pathogenesis is restricted to the oviduct tissue rather than the entire upper genital tract. Interestingly, both the p47phox-deficient and -sufficient mice displayed similar levels of chlamydial live organism shedding from the lower genital tract, suggesting that the NADPH oxidase is not required for the mouse control of chlamydial infection in the lower genital tract. Furthermore, the p47phox deficiency did not affect the infectious organism burden in the upper genital tract tissues, indicating that the NADPH-oxidase activity is not necessary for the mouse prevention of chlamydial ascension from the lower to upper genital tracts. However, the p47phox-defieicnt mice displayed a significantly reduced chronic inflammatory infiltration in the oviduct but not uterine tissues, supporting the finding that the NADPH oxidase activity is required for chlamydial induction of dilation in the oviduct but not the endometrial glandular duct. Thus, we have demonstrated a significant role of the host NADPH oxidase in promoting chronic inflammatory pathology in the oviduct following chlamydial infection.
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Affiliation(s)
- Jin Dai
- College of Life Sciences, Hunan Normal University, 36 Lushan Rd., Changsha 410081, Hunan Province, PR China; Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Lingli Tang
- Second Xiangya Hospital, No. 139 Renmin Rd., Changsha 410011, Hunan Province, PR China
| | - Jianlin Chen
- Second Xiangya Hospital, No. 139 Renmin Rd., Changsha 410011, Hunan Province, PR China
| | - Ping Yu
- Xiangya School of Medicine, Central South University, 88 Xiangya Rd., Changsha 410008, Hunan Province, PR China
| | - Ze Chen
- College of Life Sciences, Hunan Normal University, 36 Lushan Rd., Changsha 410081, Hunan Province, PR China.
| | - 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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The Chromosome-Encoded Hypothetical Protein TC0668 Is an Upper Genital Tract Pathogenicity Factor of Chlamydia muridarum. Infect Immun 2015; 84:467-79. [PMID: 26597987 DOI: 10.1128/iai.01171-15] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/17/2015] [Indexed: 12/25/2022] Open
Abstract
We previously associated a missense mutation of the tc0668 gene of serial in vitro-passaged Chlamydia muridarum, a murine model of human urogenital C. trachomatis, with severely attenuated disease development in the upper genital tract of female mice. Since these mutants also contained a TC0237 Q117E missense mutation that enhances their in vitro infectivity, an effort was made here to isolate and characterize a tc0668 single mutant to determine its individual contribution to urogenital pathogenicity. Detailed genetic analysis of C. muridarum passages revealed a truncated variant with a G216* nonsense mutation of the 408-amino-acid TC0668 protein that does not produce a detectable product. Intracellular growth and infectivity of C. muridarum in vitro remain unaffected in the absence of TC0668. Intravaginal inoculation of the TC0668 null mutant into C3H/HeJ mice results in a typical course of lower genital tract infection but, unlike a pathogenic isogenic control, is unable to elicit significant chronic inflammation of the oviduct and fails to induce hydrosalpinx. Thus, TC0668 is demonstrated as an important chromosome-encoded urogenital pathogenicity factor of C. muridarum and the first with these characteristics to be discovered for a Chlamydia pathogen.
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30
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Quantitative In Vivo Detection of Chlamydia muridarum Associated Inflammation in a Mouse Model Using Optical Imaging. Mediators Inflamm 2015; 2015:264897. [PMID: 26663988 PMCID: PMC4667028 DOI: 10.1155/2015/264897] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/29/2015] [Indexed: 01/14/2023] Open
Abstract
Chlamydia trachomatis is a bacterial sexually transmitted disease with over 1.3 million cases reported to the CDC in 2010. While Chlamydia infection is easily treated with antibiotics, up to 70% of infections are asymptomatic and go untreated. The current mouse model relies on invasive upper genital tract gross pathology readouts at ~60-80 days postinfection. High throughput optical imaging through the use of biomarkers has been successfully used to quickly evaluate several disease processes. Here we evaluate Neutrophil Elastase 680 (Elastase680) for its ability to measure Chlamydia muridarum associated inflammation in live mice using fluorescence molecular tomography (FMT) and In Vivo Imaging System (IVIS). Optical imaging was able to distinguish with statistical significance between vaccinated and nonvaccinated mice as well as mock-challenged and challenged mice 2 weeks after challenge which was 9 weeks sooner than typical gross pathological assessment. Immunohistochemistry confirmed the presence of neutrophils and correlated well with both in vivo and ex vivo imaging. In this report we demonstrate that Elastase680 can be used as a molecular imaging biomarker for inflammation associated with chlamydial infection in a mouse model and that these biomarkers can significantly decrease the time for pathology evaluation and thus increase the rate of therapeutics discovery.
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Gracey E, Baglaenko Y, Prayitno N, Van Rooijen N, Akram A, Lin A, Chiu B, Inman RD. Pulmonary Chlamydia muridarum challenge activates lung interstitial macrophages which correlate with IFN-γ production and infection control in mice. Eur J Immunol 2015; 45:3417-30. [PMID: 26344246 DOI: 10.1002/eji.201545874] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 07/23/2015] [Accepted: 09/01/2015] [Indexed: 11/09/2022]
Abstract
Protective immunity to the pathogen Chlamydia is dependent on a robust IFN-γ response generated by innate and adaptive lymphocytes. Here we assess the role of the macrophage in orchestrating a protective response in vivo to the murine pathogen, Chlamydia muridarum. During acute pulmonary and peritoneal infection, resident macrophages in both sites are infected with C. muridarum and adopt an inflammatory phenotype. In the lung, this activation is restricted to interstitial macrophages, which harbor higher levels of C. muridarum 16sRNA than alveolar macrophages. We examined innate and adaptive lymphocyte activation in the peritoneal cavity with macrophage depletion and with adoptive transfer of infected macrophages. These experiments demonstrate macrophage activation correlates with a protective IFN-γ response and effective control of C. muridarum. These studies suggest that a quantitative or qualitative alteration in macrophages may play a key role in the development of Chlamydia-associated diseases.
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Affiliation(s)
- Eric Gracey
- Department of Immunology, University of Toronto, Canada.,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | - Yuriy Baglaenko
- Department of Immunology, University of Toronto, Canada.,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | | | - Nico Van Rooijen
- Vrije Universiteit, Vrije Universiteit Medical Center, Department of Molecular Cell Biology, Amsterdam, The Netherlands
| | - Ali Akram
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | - Aifeng Lin
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | - Basil Chiu
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
| | - Robert D Inman
- Department of Immunology, University of Toronto, Canada.,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, Canada
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In Vivo and Ex Vivo Imaging Reveals a Long-Lasting Chlamydial Infection in the Mouse Gastrointestinal Tract following Genital Tract Inoculation. Infect Immun 2015; 83:3568-77. [PMID: 26099591 DOI: 10.1128/iai.00673-15] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 06/18/2015] [Indexed: 12/20/2022] Open
Abstract
Intravaginal infection with Chlamydia muridarum in mice can ascend to the upper genital tract, resulting in hydrosalpinx, a pathological hallmark for tubal infertility in women infected with C. trachomatis. Here, we utilized in vivo imaging of C. muridarum infection in mice following an intravaginal inoculation and confirmed the rapid ascent of the chlamydial organisms from the lower to upper genital tracts. Unexpectedly, the C. muridarum-derived signal was still detectable in the abdominal area 100 days after inoculation. Ex vivo imaging of the mouse organs revealed that the long-lasting presence of the chlamydial signal was restricted to the gastrointestinal (GI) tract, which was validated by directly measuring the chlamydial live organisms and genomes in the same organs. The C. muridarum organisms spreading from the genital to the GI tracts were detected in different mouse strains and appeared to be independent of oral or rectal routes. Mice prevented from orally taking up excretions also developed the long-lasting GI tract infection. Inoculation of C. muridarum directly into the upper genital tract, which resulted in a delayed vaginal shedding of live organisms, accelerated the chlamydial spreading to the GI tract. Thus, we have demonstrated that the genital tract chlamydial organisms may use a systemic route to spread to and establish a long-lasting infection in the GI tract. The significance of the chlamydial spreading from the genital to GI tracts is discussed.
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33
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Sun X, Yang Z, Zhang H, Dai J, Chen J, Tang L, Rippentrop S, Xue M, Zhong G, Wu G. Chlamydia muridarum induction of glandular duct dilation in mice. Infect Immun 2015; 83:2327-37. [PMID: 25824829 PMCID: PMC4432733 DOI: 10.1128/iai.00154-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 03/20/2015] [Indexed: 12/19/2022] Open
Abstract
Although Chlamydia-induced hydrosalpinx in women and mice has been used as a surrogate marker for tubal infertility, the medical relevance of nontubal pathologies, such as uterine horn dilation, developed in mice following chlamydial infection remains unclear. We now report that the uterine horn dilation correlates with glandular duct dilation detected microscopically following Chlamydia muridarum infection. The dilated glandular ducts pushed the uterine horn lumen to closure or dilation and even broke through the myometrium to develop extrusion outside the uterine horn. The severity scores of uterine horn dilation observed macroscopically correlated well with the number of cross sections of the dilated glandular ducts counted under microscopy. Chlamydial infection was detected in the glandular epithelial cells, potentially leading to inflammation and dilation of the glandular ducts. Direct delivery of C. muridarum into the mouse uterus increased both uterine horn/glandular duct dilation and hydrosalpinx. However, the chlamydial plasmid, which is essential for the induction of hydrosalpinx, was not required for the induction of uterine horn/glandular duct dilation. Screening 12 strains of mice for uterine horn dilation following C. muridarum infection revealed that B10.D2, C57BL/10J, and C57BL/6J mice were most susceptible, followed by BALB/cJ and A/J mice. Deficiency in host genes involved in immune responses failed to significantly alter the C. muridarum induction of uterine horn dilation. Nevertheless, the chlamydial induction of uterine horn/glandular duct dilation may be used to evaluate plasmid-independent pathogenicity of Chlamydia in susceptible mice.
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Affiliation(s)
- Xin Sun
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA Department of Obstetrics and Gynecology, 3rd Xiangya Hospital, Central South University of China, Changsha, Hunan, People's Republic of China
| | - Zhangsheng Yang
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Hongbo Zhang
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA Department of Pathology, 2nd Xiangya Hospital, Central South University of China, Changsha, Hunan, People's Republic of China
| | - Jin Dai
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Jianlin Chen
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA Department of Obstetrics and Gynecology, 2nd Xiangya Hospital, Central South University of China, Changsha, Hunan, People's Republic of China
| | - Lingli Tang
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA Department of Clinical Diagnosis, 2nd Xiangya Hospital, Central South University of China, Changsha, Hunan, People's Republic of China
| | - Sheena Rippentrop
- Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Min Xue
- Department of Obstetrics and Gynecology, 3rd Xiangya Hospital, Central South University of China, Changsha, Hunan, People's Republic of China
| | - Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Ganqiu Wu
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA Department of Histology and Embryology, Xiangya School of Medicine, Central South University of China, Changsha, Hunan, People's Republic of China
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Plasmid-Encoded Pgp5 Is a Significant Contributor to Chlamydia muridarum Induction of Hydrosalpinx. PLoS One 2015; 10:e0124840. [PMID: 25915629 PMCID: PMC4411118 DOI: 10.1371/journal.pone.0124840] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/18/2015] [Indexed: 12/22/2022] Open
Abstract
We have previously shown that the plasmid-encoded Pgp3 is a major virulence factor for C. muridarum induction of hydrosalpinx. We now report that Pgp5 also plays a significant role in the development of hydrosalpinx following C. muridarum induction. Pgp5 deficiency was introduced via either in-frame deletion (CM-Δpgp5) or premature stop codon installation (CM-pgp5S). Mice infected with either CM-Δpgp5 or CM-pgp5S developed hydrosalpinges at significantly reduced levels with an incidence rate of <40% and a mean severity score of 2 or less. In contrast, 80% or more mice developed hydrosalpinx with a severity score of >3 when mice were infected with Pgp5-sufficient C. muridarum (plasmid-competent wild type or plasmid-free C. muridarum transformed with a full plasmid or depleted of pgp7 gene). The attenuated pathogenicity of the Pgp5-deficient C. muridarum correlated with a significantly reduced level of ascending infection in the oviduct tissue despite the similar overall shedding courses between mice infected with Pgp5-deficeint versus sufficient C. muridarum. Furthermore, in the oviducts of mice infected with Pgp5-deficient C. muridarum, significantly lower levels of inflammatory cell infiltration and cytokine production were detected. Thus, Pgp5 is a significant plasmid-encoded virulence factor for C. muridarum pathogenicity in the upper genital tract.
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35
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Intrauterine infection with plasmid-free Chlamydia muridarum reveals a critical role of the plasmid in chlamydial ascension and establishes a model for evaluating plasmid-independent pathogenicity. Infect Immun 2015; 83:2583-92. [PMID: 25870225 DOI: 10.1128/iai.00353-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 04/06/2015] [Indexed: 12/18/2022] Open
Abstract
Intravaginal infection with plasmid-competent but not plasmid-free Chlamydia muridarum induces hydrosalpinx in mouse upper genital tract, indicating a critical role of the plasmid in chlamydial pathogenicity. To evaluate the contribution of the plasmid to chlamydial ascension and activation of tubal inflammation, we delivered plasmid-free C. muridarum directly into the endometrium by intrauterine inoculation. We found that three of the six mouse strains tested, including CBA/J, C3H/HeJ, and C57BL/6J, developed significant hydrosalpinges when 1 × 10(7) inclusion-forming units (IFU) of plasmid-free C. muridarum were intrauterinally inoculated. Even when the inoculum was reduced to 1 × 10(4) IFU, the CBA/J mice still developed robust hydrosalpinx. The hydrosalpinx development in CBA/J mice correlated with increased organism ascension to the oviduct following the intrauterine inoculation. The CBA/J mice intravaginally infected with the same plasmid-free C. muridarum strain displayed reduced ascending infection and failed to develop hydrosalpinx. These observations have demonstrated a critical role of the plasmid in chlamydial ascending infection. The intrauterine inoculation of the CBA/J mice with plasmid-free C. muridarum not only resulted in more infection in the oviduct but also stimulated more inflammatory infiltration and cytokine production in the oviduct than the intravaginal inoculation, suggesting that the oviduct inflammation can be induced by plasmid-independent factors, which makes the hydrosalpinx induction in CBA/J mice by intrauterine infection with plasmid-free C. muridarum a suitable model for investigating plasmid-independent pathogenic mechanisms.
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In vitro passage selects for Chlamydia muridarum with enhanced infectivity in cultured cells but attenuated pathogenicity in mouse upper genital tract. Infect Immun 2015; 83:1881-92. [PMID: 25712926 DOI: 10.1128/iai.03158-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/13/2015] [Indexed: 12/30/2022] Open
Abstract
Although modern Chlamydia muridarum has been passaged for decades, there are no reports on the consequences of serial passage with strong selection pressure on its fitness. In order to explore the potential for Pasteurian selection to induce genomic and phenotypic perturbations to C. muridarum, a starter population was passaged in cultured cells for 28 generations without standard infection assistance. The resultant population, designated CMG28, displays markedly reduced in vitro dependence on centrifugation for infection and low incidence and severity of upper genital tract pathology following intravaginal inoculation into mice compared to the parental C. muridarum population, CMG0. Deep sequencing of CMG0 and CMG28 revealed novel protein variants in the hypothetical genes TC0237 (Q117E) and TC0668 (G322R). In vitro attachment assays of isogenic plaque clone pairs with mutations in either TC0237 and TC0668 or only TC0237 reveal that TC0237(Q117E) is solely responsible for enhanced adherence to host cells. Paradoxically, double mutants, but not TC0237(Q117E) single mutants, display severely attenuated in vivo pathogenicity. These findings implicate TC0237 and TC0668 as novel genetic factors involved in chlamydial attachment and pathogenicity, respectively, and show that serial passage under selection pressure remains an effective tool for studying Chlamydia pathogenicity.
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Plasmid-encoded Pgp3 is a major virulence factor for Chlamydia muridarum to induce hydrosalpinx in mice. Infect Immun 2014; 82:5327-35. [PMID: 25287930 DOI: 10.1128/iai.02576-14] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hydrosalpinx induction in mice by Chlamydia muridarum infection, a model that has been used to study C. trachomatis pathogenesis in women, is known to depend on the cryptic plasmid that encodes eight genes designated pgp1 to pgp8. To identify the plasmid-encoded pathogenic determinants, we evaluated C. muridarum transformants deficient in the plasmid-borne gene pgp3, -4, or -7 for induction of hydrosalpinx. C. muridarum transformants with an in-frame deletion of either pgp3 or -4 but not -7 failed to induce hydrosalpinx. The deletion mutant phenotype was reproduced by using transformants with premature termination codon insertions in the corresponding pgp genes (to minimize polar effects inherent in the deletion mutants). Pgp4 is known to regulate pgp3 expression, while lack of Pgp3 does not significantly affect Pgp4 function. Thus, we conclude that Pgp3 is an effector virulence factor and that lack of Pgp3 may be responsible for the attenuation in C. muridarum pathogenicity described above. This attenuated pathogenicity was further correlated with a rapid decrease in chlamydial survival in the lower genital tract and reduced ascension to the upper genital tract in mice infected with C. muridarum deficient in Pgp3 but not Pgp7. The Pgp3-deficient C. muridarum organisms were also less invasive when delivered directly to the oviduct on day 7 after inoculation. These observations demonstrate that plasmid-encoded Pgp3 is required for C. muridarum survival in the mouse genital tract and represents a major virulence factor in C. muridarum pathogenesis in mice.
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Complement factor C5 but not C3 contributes significantly to hydrosalpinx development in mice infected with Chlamydia muridarum. Infect Immun 2014; 82:3154-63. [PMID: 24842924 DOI: 10.1128/iai.01833-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hydrosalpinx is a pathological hallmark of tubal infertility associated with chlamydial infection. However, the mechanisms of hydrosalpinx remain unknown. Here, we report that complement factor 5 (C5) contributes significantly to chlamydial induction of hydrosalpinx. Mice lacking C5 (C5(-/-)) failed to develop any hydrosalpinx, while ∼42% of the corresponding wild-type mice (C5(+/+)) did so following intravaginal infection with Chlamydia muridarum. Surprisingly, deficiency in C3 (C3(-/-)), an upstream component of the complement system, did not affect mouse susceptibility to chlamydial induction of hydrosalpinx. Interestingly, C5 activation was induced by chlamydial infection in oviducts of C3(-/-) mice, explaining why the C3(-/-) mice remained susceptible to chlamydial induction of hydrosalpinx. Similar levels of live chlamydial organisms were recovered from oviduct tissues of both C5(-/-) and C5(+/+) mice, suggesting that C5 deficiency did not affect C. muridarum ascending infection. Furthermore, C5(-/-) mice were still more resistant to hydrosalpinx induction than C5(+/+) mice, even when live C. muridarum organisms were directly delivered into the upper genital tract, both confirming the role of C5 in promoting hydrosalpinx and indicating that the C5-facilitated hydrosalpinx was not due to enhancement of ascending infection. The C5(-/-) mice displayed significantly reduced lumenal inflammatory infiltration and cytokine production in oviduct tissue, suggesting that C5 may contribute to chlamydial induction of hydrosalpinx by enhancing inflammatory responses.
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