Mechanisms and Correlates of Immune Protection against Genital Chlamydia in Humans

沙眼衣原体(CT)感染非常普遍，并导致严重的生殖疾病。 尽管采取了预防和控制措施，但CT感染率仍处于历史高位，再次感染很常见， 这表明对CT的保护性免疫通常是不够的。控制CT感染需要接种疫苗。我们的 长期目标是确定介导人类对CT的保护的免疫遗传因素，以促进 疫苗研发。我们发现CT特异性的全身性CD4IFN-g反应与较低的CT有关 女性再感染的频率。我们在宫颈阴道灌洗液中检测到干扰素-g，但没有鉴定出细胞。 来源是因为灌洗液中活的粘膜单个核细胞(MMC)计数太低，无法进行功能免疫 学习。为了解决这个问题，我们分析了月经血(MB)作为MMC来源，这产生了足够的MMC 算了。MB MMC研究的初步数据显示，产生干扰素-g的组织驻留记忆T细胞(TRMS) 作为干扰素-g的来源，但其他MMC来源的干扰素-g尚未被研究。干扰素-g保护机制的研究进展 女性对CT的危害仍有待阐明，但体外研究表明，它们可能包括色氨酸缺乏， 活性氮中间体、葡萄糖饥饿和细胞溶解。我们的初步数据表明，microRNA (MIR)和遗传变异也影响CT再感染风险。我们发现了SELECT基因miR的差异表达 MIRS与CT再感染的关系。我们在两个不同的队列中显示，人类白细胞抗原-DQB1*06与CT相关 然而，它在再感染中的作用尚未被确定为邻近的可能 处于连锁不平衡(LD)还没有研究。此应用程序的目标是弥合 通过确定干扰素-g的机制和其他效应反应来了解开发CT疫苗所需的知识 影响对CT再感染的获得性免疫，以及影响再感染风险的MIR和基因变异。 我们的中心假设是对CT再感染的保护是一个包括干扰素-g在内的多因素过程 由CT特异性T细胞和其他效应器反应产生，可能受miRs和基因调控 变种。利用一组患有CT再感染和未再感染CT的女性的样本和数据，我们现在的目标是进一步 通过其他研究验证这一假设：目标1：评估系统性CD4T 细胞和MMC介导对CT再感染的保护--干扰素-g机制和其他效应反应 将通过基于流式细胞仪的方法和/或聚合酶链式反应(Subaim)来测量来自系统的CD4T细胞和MMC 1a)和用miR qPCR阵列(Subaim 1b)检测T细胞相关miRs的血清；以及目标2：确定 LD患者中是否存在HLADQB1*06或其他邻近的HLA变异体可强烈预测CT再感染风险--DNA 对人类白细胞抗原-DQ和-DR区域进行测序，并进行精细作图，以确定可能的风险人类白细胞抗原变异 使用AIM 1分析免疫反应数据。这项创新性研究将推动CT疫苗的发展。

Chlamydia trachomatis (CT) infection is highly prevalent and causes significant reproductive morbidity. Despite prevention and control measures, CT infection rates are at an all-time high and reinfection is common, suggesting that protective immunity to CT is often insufficient. Control of CT infection will require a vaccine. Our long-term goal is to determine immunogenetic factors that mediate protection against CT in humans to facilitate vaccine development. We found that a CT-specific systemic CD4+ IFN-g response was associated with lower CT reinfection frequency in women. We detected IFN-g in cervicovaginal lavages but could not identify the cellular source because viable mucosal mononuclear cells (MMC) counts in lavages were too low for functional immune studies. To solve this, we analyzed menstrual blood (MB) as an MMC source, which yielded sufficient MMC counts. Preliminary data from MB MMC studies revealed IFN-g-producing tissue-resident memory T cells (Trms) as an IFN-g source, but other MMC sources of IFN-g have not been studied. Mechanisms by which IFN-g protects against CT in women remain to be elucidated, but in vitro studies suggest they may include tryptophan depletion, reactive nitrogen intermediates, glucose starvation, and cytolysis. Our preliminary data suggests that microRNAs (miRs) and genetic variants also influence CT reinfection risk. We found differential miR expression of select miRs in relation to CT reinfection. We showed in two distinct cohorts that HLA-DQB1*06 was associated with CT reinfection risk, however, its role in reinfection has not been established as neighboring HLA variants that may be in linkage disequilibrium (LD) have not been studied. The goal of this application is to bridge the gap in knowledge needed for CT vaccine development by determining IFN-g mechanisms and other effector responses that influence adaptive immunity to CT reinfection and the miRs and gene variants that affect risk for reinfection. Our central hypothesis is that protection against CT reinfection is a multifactorial process including IFN-g produced by CT-specific T cells and other effector responses, which may be regulated by miRs and genetic variants. Using samples and data from a cohort of women with vs. without CT reinfection, we now aim to further test this hypothesis through additional research: Aim 1: Evaluate mechanisms through which systemic CD4+ T cells and MMCs mediate protection against CT reinfection - IFN-g mechanisms and other effector responses from systemic CD4+ T cells and MMCs will be measured by flow-cytometry-based methods and/or PCR (Subaim 1a) and sera tested for T cell-associated miRs with a miR qPCR array (Subaim 1b); and Aim 2: Determine whether HLA-DQB1*06 or other neighboring HLA variants in LD strongly predicts CT reinfection risk - DNA will be sequenced for the HLA-DQ and -DR region and fine-mapping done to identify putative risk HLA variants for analyses with Aim 1 immune response data. This innovative research will advance CT vaccine development.