T-cell mediated immunity in chlamydia genital infection

描述(申请人提供)：沙眼衣原体，一种专性细胞内细菌，导致大多数细菌性传播感染(STI)病例。美国每年新增300万感染病例，通常会导致盆腔炎、异位妊娠和输卵管不孕，这些疾病每年给医疗行业造成数十亿美元的损失。调节性T细胞(Tregs)具有抑制T细胞反应和预防宿主组织炎症的能力。设计一种限制上生殖道炎症(UGT)的方法可能会预防衣原体感染后的后遗症。我们已经鉴定出在衣原体生殖道感染过程中出现在重叠但不同位置的CD4+FoxP3+Tregs和CD8+CXCR5+Tregs，它们可能通过不同的方式影响感染。我们的初步数据表明，在生殖道和次级淋巴组织感染期间，存在CD4+FoxP3+Tregs。在衣原体生殖器感染过程中，PDC数量的减少改变了Th1/Tregs的平衡，提示PDC参与了CD4+FoxP3+Tregs的产生。相比之下，在感染NAOVE小鼠之前，CD8+CXCR5+Tregs细胞就已经存在。衣原体感染后，CD8+CXCR5+Tregs的缺失导致输卵管周围淋巴细胞显著积聚和胶原沉积。感染通过诱导FoxP3的表达，调节体内MoPn反应性T细胞的细胞因子分泌，逆转UGT中淋巴细胞的聚集和胶原沉积，从而刺激Tregs的功能。综上所述，我们假设FoxP3+Tregs调控衣原体感染和UGT组织炎症，并提出以下特异性目标：1.明确CD8+CXCR5+Tregs控制生殖道衣原体感染的机制(S)。2.探讨CD4+FoxP3+Tregs在衣原体生殖道感染中的作用。我们将通过体内和体外沙眼衣原体(MoPn)小鼠感染生殖器的实验、过继转移、流式细胞术、ELISA法和CFSE Tregs抑制试验，使用CXCR5和FoxP3-Delta-EGFP基因敲除和FoxP3-GFP敲除、OT-II转基因小鼠和FoxP3-DTR和CD11c-DTR的条件基因敲除来验证这些目标。宿主组织炎症的病因学研究也将促进其他感染、移植排斥反应和自身免疫反应后免疫介导的病理的预防。了解Tregs在UGT炎症中的作用对于开发针对衣原体感染和其他STI的新型免疫调节疗法至关重要。这位名为凯瑟琳·A·凯利博士的PI在研究衣原体感染后的小鼠UGT炎症方面拥有独特的经验，并组建了一个团队，使她能够做出重大贡献。公共卫生意义：沙眼衣原体是一种专性细胞内细菌，在美国引起的细菌性传播感染(STI)病例最多，每年可导致约100万例免疫介导的盆腔炎(PID)和/或受感染女性的不孕不育。Pid和不孕症的治疗每年给美国医疗保健系统带来数十亿美元的负担，这项提案研究了一种潜在的方法(FoxP3+T调节细胞)，以减少因衣原体感染而出现免疫介导后遗症的个体数量。

DESCRIPTION (provided by applicant): Chlamydia trachomatis, an obligate intracellular bacterium, causes the most cases of bacterial sexually transmitted infections (STIs). Three million new cases of infection occur in the US each year and commonly result in pelvic inflammatory disease (PID), ectopic pregnancy and tubal infertility which costs the health care industry billions of dollars annually. Regulatory T cells (Tregs) have the ability to suppress T cell responses and prevent host tissue inflammation. Devising a means for limiting inflammation in the upper genital tract (UGT) would likely prevent the sequelae that follow chlamydial infection. We have identified CD4+FoxP3+Tregs and CD8+CXCR5+Tregs that appear in overlapping but different locations during chlamydial genital infection and likely influence infection by distinct means. Our preliminary data indicates that CD4+FoxP3+Tregs are present during infection in the genital tract and secondary lymphoid tissue. Reduction in the number of pDC alters the balance of Th1/Tregs during chlamydial genital infection and suggests that pDC are involved in production of CD4+FoxP3+Tregs. In contrast, CD8+CXCR5+Tregs cells are present in naove mice prior to infection. The lack of CD8+CXCR5+Tregs result in marked lymphocyte accumulation and collagen deposition surrounding oviducts after chlamydial infection. Infection stimulates Tregs function by inducing the expression of FoxP3, regulating cytokine secretion by MoPn-responsive T cells in vivo and reversing lymphocyte accumulation and collagen deposition in the UGT. Taken together, we hypothesize that FoxP3+Tregs regulate chlamydial infection and UGT tissue inflammation and propose the following specific aims: 1. Identify mechanism(s) by which CD8+CXCR5+ Tregs control chlamydial genital infection. 2. Evaluate the contribution of CD4+FoxP3+Tregs on Chlamydia genital infection. We will test these Aims with in vivo and in vitro experiments of genital infection with the mouse agent of C. trachomatis (MoPn), adoptive transfer, flow cytometry, ELISA, and CFSE Tregs suppressor assays using CXCR5 & FoxP3-Delta-EGFP knockout & FoxP3-GFP knockin, OT-II transgenic mice and the conditional knockouts for FoxP3-DTR & CD11c-DTR. Investigation of the etiology of host tissue inflammation will also advance the prevention of immune-mediated pathology following other infections, transplantation rejection and autoimmune reactions. Understanding the role of Tregs in UGT inflammation is essential for developing novel immunomodulatory therapeutics for chlamydial infection and other STI's. The PI, Dr. Kathleen A. Kelly is uniquely experienced to investigate murine UGT inflammation following Chlamydia infection and has assembled a team which will enable her to make significant contributions. PUBLIC HEALTH RELEVANCE: Benefits for Public Health Chlamydia trachomatis, an obligate intracellular bacterium, causes the most cases of bacterial sexually transmitted infections (STIs) in the US and can result in about one million cases of immune- mediated pelvic inflammatory disease (PID) and/or infertility in infected females annually. Treating PID and infertility burdens the US health care system by billions of dollars annually and this proposal examines a potential means (FoxP3+ T regulatory cells) of reducing the number of individuals which develop immune-mediated sequelae following Chlamydia STIs.