Determinants of protection in HIV-exposed seronegative men

描述（由申请人提供）：虽然绝大多数人对艾滋病毒感染易感，但极少数人即使在多次暴露后仍未感染。对这些人的研究导致了一种遗传多态性（CCR 5 32）的鉴定，在纯合状态下，提供了对收购的保护。然而，这一发现只说明了接触后未受感染的少数人;因此，必须采取其他机制提供保护。在这个应用程序中，我们提出了一个探索性的分析遗传和先天宿主防御因素，可能发挥作用，保护免受艾滋病毒感染。通过这种应用，我们建议检查a）200名与男性发生性关系的高暴露血清阴性（HESN）男性（MSM），B）60名低风险MSM对照（LRC）和c）60名HIV感染男性的队列中的保护机制。与以前的倡议和我们的建议的一个显着的创新方面不同，我们将不仅选择具有极高的自我报告的HIV暴露风险的受试者，而且将尝试通过使用多层方法检测外周循环和粘膜中的HIV特异性回忆反应来详细描述那些具有明确的生物暴露证据的受试者。通过对最有可能暴露的受试者进行强有力的区分，我们将检查粘膜部位和外周血中对HIV复制的内在抵抗力。我们将检查HIV辅助受体CCR 5的表达和占用肽抑制剂在HIV暴露的粘膜部位，并将检查粘膜T细胞的“静止”以及我们首次报道的HESN血友病患者的循环T细胞。我们将详细探讨自然杀伤细胞（NK）和树突状细胞（DC）群体在粘膜和全身保护免受HIV感染中提供的先天防御作用。在非CCR 5 32纯合子的受试者中，我们将通过对来自250个HESN的血液样本进行全基因组测序来检查保护的遗传决定因素（除了用于所有其他研究的200个之外，还将收集50个HESN，以增加遗传分析的功效）。还将对来自150名HESN和60名低风险MSM对照的直肠粘膜样本进行转录谱分析。使用一组经验证的病毒学检测，受损的感染性将定位于病毒生命周期的特定阶段，以便于精确识别缺陷的来源。最后，这些数据集将被询问，以更详细地探索功能“命中”的遗传决定因素和高概率遗传“命中”的功能影响，以协调这些不同的搜索方法。这些新的和全面的分析相结合的免疫学，病毒学和遗传学的方法，使用队列在仔细定义的艾滋病毒暴露的风险，将提供关键信息的决定因素，粘膜保护艾滋病毒感染。

DESCRIPTION (provided by applicant): While the vast majority of individuals are susceptible to HIV infection, a rare subset remains uninfected even after multiple exposures. Research on these persons has led to the identification of a genetic polymorphism (CCR5 32) that, in the homozygous state, provides protection against acquisition. However, this finding accounts for only a minority of persons who remain uninfected after exposure; therefore, other mechanisms must be acting to confer protection. In this application we propose an exploratory analysis of genetic and innate host defense factors that may play a role in protection from HIV infection. With this application we propose to examine mechanisms of protection among cohorts of a) 200 highly- exposed seronegative (HESN) men who have sex with men (MSM), b) 60 low risk MSM controls (LRCs), and c) 60 HIV infected men. In a departure from previous initiatives and a markedly innovative aspect of our proposal, we will not only select subjects with an extremely high self-reported risk of HIV exposure, but will attempt to delineate in exquisite detail those wih definitive evidence of biological exposure by using a multi- layered approach to detect HIV-specific anamnestic responses in the peripheral circulation and in the mucosa. With a robust discrimination of subjects most likely to have been exposed, we will examine intrinsic resistance to HIV replication at mucosal sites and in peripheral blood. We will examine the expression and occupancy of the HIV coreceptor CCR5 by peptide inhibitors at mucosal sites of HIV exposure and will examine the "quiescence" of mucosal T cells as well as in circulating T cells that we firs reported in HESN hemophiliacs. We will explore in fine detail the role of innate defenses provided by natural killer (NK) and dendritic cell (DC) populations in mucosal and systemic protection from HIV infection., Among subjects who are not CCR5 32 homozygous we will examine the genetic determinants of protection by whole-genome sequencing of blood samples from 250 HESN (50 HESN will be collected in addition to the 200 used for all other studies to increase power of the genetic analyses). Transcriptional profiles will also be performed on rectal mucosal samples from 150 HESN and 60 low risk MSM controls. Using a set of validated virologic assays, impaired infectibility will be localized to specific stages of the viral life cyce to facilitate precise identification of the source of the defect. Finally, these data sets will be interrogated to explore in greater detail the genetic determinants of functional "hits" and the functional implications of high probability genetic "hits" in order to harmonize these different search approaches. These novel and comprehensive analyses combining immunologic, virologic and genetic approaches using cohorts at carefully defined risks of HIV exposure will provide critical information on the determinants of mucosal protection from HIV infection.