Circulating immunity protects the female reproductive tract from Chlamydia infection.
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ABSTRACT:
SUBMITTER: Labuda JC
PROVIDER: S-EPMC8166081 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The innate immune system senses pathogens through pattern-recognition receptors (PRRs) that signal to induce effector cytokines, such as type I interferons (IFNs). We characterized IFN-? as a type I IFN because it signaled via the Ifnar1 and Ifnar2 receptors to induce IFN-regulated genes. In contrast to other type I IFNs, IFN-? was not induced by known PRR pathways; instead, IFN-? was constitutively expressed by epithelial cells of the female reproductive tract (FRT) and was hormonally regulated. Ifn-?-deficient mice had increased susceptibility to infection of the FRT by the common sexually transmitted infections (STIs) herpes simplex virus 2 and Chlamydia muridarum. Thus, IFN-? is a potent antipathogen and immunoregulatory cytokine that may be important in combating STIs that represent a major global health and socioeconomic burden.
| S-EPMC3617553 | biostudies-literature
Project description:Although Zika virus (ZIKV) can be transmitted sexually and cause congenital birth defects, immune control mechanisms in the female reproductive tract (FRT) are not well characterized. Here we show that treatment of primary human vaginal and cervical epithelial cells with interferon (IFN)-α/β or IFN-λ induces host defense transcriptional signatures and inhibits ZIKV infection. We also assess the effects of IFNs on intravaginal infection of the FRT using ovariectomized mice treated with reproductive hormones. We find that mice receiving estradiol are protected against intravaginal ZIKV infection, independently of IFN-α/β or IFN-λ signaling. In contrast, mice lacking IFN-λ signaling sustain greater FRT infection when progesterone is administered. Exogenous IFN-λ treatment confers an antiviral effect when mice receive both estradiol and progesterone, but not progesterone alone. Our results identify a hormonal stage-dependent role for IFN-λ in controlling ZIKV infection in the FRT and suggest a path for minimizing sexual transmission of ZIKV in women.
| S-EPMC6336786 | biostudies-literature
Project description:While Chlamydia trachomatis infections are frequently asymptomatic, mechanisms that regulate host response to this intracellular Gram-negative bacterium remain undefined. This investigation thus used peripheral blood mononuclear cells and endometrial tissue from women with or without Chlamydia genital tract infection to better define this response. Initial genome-wide microarray analysis revealed highly elevated expression of matrix metalloproteinase 10 and other molecules characteristic of Type 2 immunity (e.g., fibrosis and wound repair) in Chlamydia-infected tissue. This result was corroborated in flow cytometry and immunohistochemistry studies that showed extant upper genital tract Chlamydia infection was associated with increased co-expression of CD200 receptor and CD206 (markers of alternative macrophage activation) by endometrial macrophages as well as increased expression of GATA-3 (the transcription factor regulating TH2 differentiation) by endometrial CD4(+) T cells. Also among women with genital tract Chlamydia infection, peripheral CD3(+) CD4(+) and CD3(+) CD4(-) cells that proliferated in response to ex vivo stimulation with inactivated chlamydial antigen secreted significantly more interleukin (IL)-4 than tumor necrosis factor, interferon-γ, or IL-17; findings that repeated in T cells isolated from these same women 1 and 4 months after infection had been eradicated. Our results thus newly reveal that genital infection by an obligate intracellular bacterium induces polarization towards Type 2 immunity, including Chlamydia-specific TH2 development. Based on these findings, we now speculate that Type 2 immunity was selected by evolution as the host response to C. trachomatis in the human female genital tract to control infection and minimize immunopathological damage to vital reproductive structures.
| S-EPMC3603585 | biostudies-literature
Project description:BackgroundChlamydia trachomatis and Mycoplasma infections have been regarded as severe challenges to public health worldwide because their potential risk of leading to serious reproductive complications. C. trachomatis is the most common sexually transmitted bacterial infections and the prevalence has been increasing in recent years. As a newly discovered pathogen, Mycoplasma genitalium has gradually been recognized as important sexually transmitted infection and even been called a "new chlamydia". There are no official epidemiological data of M. genitalium in China especially in women with lower reproductive tract infection. This work aims to understand the prevalence and risk factors of M. genitalium and C. trachomatis in women with lower reproductive tract infections and to provide reference for the formulation of health policy in China.MethodsThis study was conducted in the gynecological clinics of 12 hospitals geographically located in different regions in China. Women with purulent cervical secretions or abnormal vaginal microecology were included as the research group, and those with normal vaginal microecology and cervical secretions were included as the control group. A total of 2190 participants were recruited in this project including 1357 of research group and 833 of control group. All participants were required to complete questionnaires, whose vaginal discharge were collected for vaginal microecology test and cervical discharge for detection of M. genitalium and C. trachomatis.ResultsThe prevalence of C. trachomatis and M. genitalium were 7.1% (96/1357) and 3.8% (51/1357), respectively in research group. The prevalence of C. trachomatis and M. genitalium varied in different regions. Infection rates of C. trachomatis and M. genitalium were higher in women with abnormal vaginal microecology (C.t P = 0.038, M.g P = 0.043), especially in women with bacterial vaginosis and mixed vaginitis, of which C. trachomatis showed statistical differences (bacterial vaginosis, P = 0.035; mixed vaginitis, P = 0.0001) and M. genitalium was close to statistical differences (bacterial vaginosis, P = 0.057; mixed vaginitis, P = 0.081). Alcoholism and abnormal vaginal microecology were positively correlated with both C. trachomatis and M. genitalium infection. Increasing age, being married and multi-parity were negatively correlated with C. trachomatis infection. There is a positive correlation between multiple sexual partners, diversed styles of sex and C. trachomatis infection.ConclusionsWomen with lower genital dysbiosis have an increased risk of C. trachomatis and M. genitalium. The overall prevalence of M. genitalium is lower than that of C. trachomatis, while they have similarities in the characteristics of infection. Although M. genitalium is not routinely screened as C. trachomatis in young women, attention should be paid to M. genitalium infection in young women with abnormal vaginal microecology or having childbearing needs.
| S-EPMC9814310 | biostudies-literature
Project description:The protein basic helix-loop-helix family member e40 (BHLHE40) is a transcription factor recently emerged as a key regulator of host immunity to infections, autoimmune diseases and cancer. In this study, we investigated the role of Bhlhe40 in protective T cell responses to the intracellular bacterium Chlamydia in the female reproductive tract (FRT). Mice deficient in Bhlhe40 exhibited severe defects in their ability to control Chlamydia muridarum shedding from the FRT. The heightened bacterial burdens in Bhlhe40-/- mice correlated with a marked increase in IL-10-producing T regulatory type 1 (Tr1) cells and decreased polyfunctional CD4 T cells co-producing IFN-γ, IL-17A and GM-CSF. Genetic ablation of IL-10 or functional blockade of IL-10R increased CD4 T cell polyfunctionality and partially rescued the defects in bacterial control in Bhlhe40-/- mice. Using single-cell RNA sequencing coupled with TCR profiling, we detected a significant enrichment of stem-like T cell signatures in Bhlhe40-deficient CD4 T cells, whereas WT CD4 T cells were further down on the differentiation trajectory with distinct effector functions beyond IFN-γ production by Th1 cells. Altogether, we identified Bhlhe40 as a key molecular driver of CD4 T cell differentiation and polyfunctional responses in the FRT against Chlamydia.
| S-EPMC10846703 | biostudies-literature
Project description:Interferon ε (IFNε), a unique type I IFN, is thought to protect the host against sexually transmitted infections. Unlike conventional type I IFNs (e.g., IFNα/β), whose expression is undetectable at baseline, IFNε expression is detectable in the epithelium of mucosal tissues, particularly the female reproductive tract (FRT). We found that IFNε expression was not limited to epithelial cells at the FRT. Importantly, in contrast to previous reports, IFNε expression in plasmacytoid dendritic cells and primary cervical epithelial cells was induced by viral infection and by activation of TLR3 or 4 in PBMCs. Induction of IFNε mRNAs was also found in cervicovaginal tissues (CVT) of Zika virus (ZIKV)-infected mice. Mice with IFNε deficiency (Ifnε-/-) did not have impaired induction of interferon-stimulated genes except IFNl, but had altered epithelial and collagen structure in the CVT. Ifnε-/- mice exhibited increased susceptibility to ZIKV infection via an intravaginal route but not via a subcutaneous route, indicating that the protective effect of IFNe was specific to the FRT. Infected Ifnε-/- mice had higher and more sustained viral loads than infected wild-type (WT) mice. Detection of ZIKV infection by single molecule in situ hybridization confirmed that virus spread faster in Ifnε-/- mice than in WT mice. Recombinant murine IFNε protected Ifnar1-/- mice against ZIKV infection when administered through an intravaginal route but not when administered through a subcutaneous route, indicating that the specific role of IFNe at the FRT is independent of IFNAR1 signaling. Our findings indicate that IFNε mediates a novel FRT-specific protective effect on mucosal immunity that limits Zika virus spread.
2023-05-11 | GSE228359 | GEO
Project description:Protective immune responses to Chlamydia infection within the female reproductive tract (FRT) are incompletely understood. MHC class II-restricted CD4 Th1 responses are believed to be vital for bacterial clearance due to their capacity to secrete IFN-γ, but an essential requirement for T-bet-expressing Th1 cells has yet to be demonstrated in the mouse model of Chlamydia infection. Here, we investigated the role of T-bet and IFN-γ in primary clearance of Chlamydia after FRT infection. Surprisingly, IFN-γ producing CD4 T cells from the FRT expressed low levels of T-bet throughout infection, suggesting that classical T-bet-expressing Th1 cells are inefficiently generated and therefore unlikely to participate in bacteria clearance. Furthermore, mice deficient in T-bet expression or with a CD4-specific T-bet deficiency cleared FRT infection similarly to wild-type controls. T-bet-deficient mice displayed significant skewing of FRT CD4 T cells towards Th17 responses, demonstrating that compensatory effector pathways are generated in the absence of Th1 cells. In marked contrast, IFN-γ-, and IFN-γR-deficient mice were able to reduce FRT bacterial burdens, but suffered systemic bacterial dissemination and 100% mortality. Together, these data demonstrate that IFN-γ signaling is essential to protect mice from fatal systemic disease, but that classical T-bet-expressing Th1 cells are non-essential for primary clearance within the FRT. Exploring the protective contribution of Th1 cells versus other CD4 effector lineages could provide important information for the generation of new Chlamydia vaccines.
| S-EPMC8901068 | biostudies-literature
Project description:The T cell response to Chlamydia genital tract infections in humans and mice is unusual in that the majority of antigen-specific CD8 T cells are not restricted by HLA/MHC class I and therefore have been referred to as “unrestricted” or “atypical”. We previously reported that a subset of unrestricted murine Chlamydia-specific CD8 T cells had an unusual cytokine polarization pattern that included IFN-ɣ and IL-13. For this report, we investigated the transcriptome of Chlamydia-specific CD8ɣ13 T cells, comparing them to Chlamydia-specific multifunctional Tc1 clones using gene expression micro array analysis. The molecular study revealed that CD8ɣ13 polarization included IL-5 in addition to IFN-γ and IL-13. Adoptive transfer studies were performed with Tc1 clone and CD8ɣ13 T cell clones to determine whether either influenced bacterial clearance or immunopathology during Chlamydia muridarum (Cm) genital tract infections. To our surprise, an adoptively transferred CD8ɣ13 T cell clone was remarkably proficient at preventing chlamydia immunopathology while the multifunctional Tc1 clone did not enhance clearance or significantly protect from immunopathology. Mapping studies with MHC class I- and class II-deficient splenocytes showed our previously published Chlamydia-specific CD8 T cell clones are MHC class II-restricted. MHC class II-restricted CD8 T cells may play important roles in protection from intracellular pathogens that limit class I antigen presentation or deplete the CD4 T cell compartment.
2020-05-21 | GSE140213 | GEO
Project description:Chlamydia spp. productively infect mucosal epithelial cells of multiple anatomical sites, including the conjunctiva, lungs, gastrointestinal (GI) tract, and urogenital tract. We, and others, previously established that chlamydial GI tropism is mediated by distinct chromosomal and plasmid factors. In this study, we describe a genital infection-attenuated Chlamydia muridarum mutant (GIAM-1) that is profoundly and specifically attenuated in the murine genital tract. GIAM-1 infected the murine GI tract similarly to wild-type (WT) Chlamydia muridarum but did not productively infect the lower genital tract of female mice, ascend to infect the upper genital tract, or cause hydrosalpinx. However, GI infection of mice with GIAM-1 elicited a transmucosal immune response that protected against subsequent genital challenge with WT Chlamydia muridarum Collectively, our results demonstrate that chlamydia mutants that are profoundly attenuated for specific organ tissues can be derived and demonstrate that live-attenuated vaccine strains that infect the GI tract, but do not elicit genital tract disease, could be used to protect against chlamydia genital tract infection and disease.IMPORTANCE Chlamydia is the most common sexually transmitted bacterial infection in the United States. Most chlamydia genital infections resolve without serious consequences; however, untreated infection in women can cause pelvic inflammatory disease and infertility. Antibiotics are very effective in treating chlamydia, but most genital infections in both men and women are asymptomatic and go undiagnosed. Therefore, there is a critical need for an effective vaccine. In this work, we show that a mutant chlamydia strain, having substantially reduced virulence for genital infection, colonizes the gastrointestinal tract and produces robust immunity to genital challenge with fully virulent wild-type chlamydia. These results are an important advance in understanding chlamydial virulence and provide compelling evidence that safe and effective live-attenuated chlamydia vaccines may be feasible.
| S-EPMC7642681 | biostudies-literature
Project description:While a primary genital tract infection with C. trachomatis stimulates partial-protection against re-infection, it may also result in severe inflammation and tissue destruction. Here we have dissected whether functional compartments exist in the genital tract that restrict Th1-mediated protective immunity. Apart from the Th1-subset, little is known about the role of other CD4(+) T cell subsets in response to a genital tract chlamydial infection. Therefore, we investigated CD4(+) T cell subset differentiation in the genital tract using RT-PCR for expression of critical transcription factors and cytokines in the upper (UGT) and lower genital tract (LGT) of female C57BL/6 mice in response to C. trachomatis serovar D infection. We found that the Th1 subset dominated the UGT, as IFN-γ and T-bet mRNA expression were high, while GATA-3 was low following genital infection with C. trachomatis serovar D. By contrast, IL-10 and GATA-3 mRNA dominated the LGT, suggesting the presence of Th2 cells. These functional compartments also attracted regulatory T cells (Tregs) differently as increased FoxP3 mRNA expression was seen primarily in the UGT. Although IL-17A mRNA was somewhat up-regulated in the LGT, no significant change in RORγ-t mRNA expression was observed, suggesting no involvement of Th17 cells. The dichotomy between the LGT and UGT was maintained during infection by IL-10 because in IL-10-deficient mice the distinction between the two compartments was completely lost and a dramatic shift to the predominance of Th1 cells in the LGT occurred. Unexpectedly, the major source of IL-10 was CD11c(+) CD11b(+) DC, probably creating an anti-inflammatory privileged site in the LGT.
| S-EPMC2973832 | biostudies-other