Mechanisms and Correlates of Immune Protection against Genital Chlamydia in Humans

沙眼衣原体（CT）感染是非常普遍的，并导致显着的生殖系统疾病的发病率。 尽管采取了预防和控制措施，但CT感染率仍处于历史最高水平，再感染很常见， 提示对CT的保护性免疫常常是不足的。控制CT感染需要疫苗。我们 长期目标是确定介导人类抗CT保护的免疫遗传因素， 疫苗研发。我们发现CT特异性全身性CD 4 + IFN-g应答与较低的CT相关， 女性再感染的频率。我们在宫颈阴道灌洗液中检测到IFN-γ，但不能鉴定细胞内IFN-γ的表达。 因为灌洗液中活的粘膜单核细胞（MMC）计数太低，无法进行功能性免疫 问题研究为了解决这个问题，我们分析了月经血（MB）作为MMC来源，这产生了足够的MMC 道理来自MB MMC研究的初步数据显示，产生IFN-g的组织驻留记忆T细胞（Trms） 作为IFN-g源，但尚未研究IFN-g的其他MMC源。IFN-g保护的机制 对妇女的CT仍有待阐明，但体外研究表明，它们可能包括色氨酸耗尽， 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， （miRs）和遗传变异也影响CT再感染风险。我们发现选择性的miR表达差异 与CT再感染相关的miR。我们在两个不同的队列中发现，HLA-DQB 1 *06与CT相关， 然而，再感染风险，其在再感染中的作用尚未确定，因为邻近的HLA变体可能 连锁不平衡（LD）尚未被研究。此应用程序的目标是弥合以下方面的差距： 通过确定IFN-g机制和其他效应反应来开发CT疫苗所需的知识 影响对CT再感染的适应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多因素的过程， 由CT特异性T细胞和其他效应器反应产生，这可能受到miR和遗传调节 变体。使用来自有与没有CT再感染的女性队列的样本和数据，我们现在的目标是进一步 通过其他研究来验证这一假设：目的1：评价系统性CD 4 + T细胞 细胞和MMCs介导对CT再感染的保护-IFN-γ机制和其他效应器应答 将通过基于流式细胞术的方法和/或PCR（Subaim 1a）和用miR qPCR阵列测试T细胞相关miR的血清（Subaim 1b）;和目的2：确定 LD中HLA-DQB 1 *06或其他邻近HLA变体是否强烈预测CT再感染风险- DNA将 对HLA-DQ和-DR区域进行测序，并进行精细定位，以确定推定的风险HLA变体， 使用Aim 1免疫应答数据进行分析。这项创新研究将推动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.