Aging compromises neutrophil-mediated innate protection against HIV in thehuman female genital tract

项目总结 所有年龄段的妇女感染艾滋病毒的主要途径是性传播。而年轻女性(15-24岁) 年)是流行地区艾滋病毒感染的高危地区，#年新的艾滋病毒感染发病率增加。 全世界都在观察老年妇女(50岁)。然而，导致预防或 艾滋病毒的获得性以及粘膜保护如何随着年龄的增长而受到影响，在很大程度上是未知的。因此，至关重要的是 确定预防HIV感染靶细胞的早期粘膜机制，以及这种保护是如何 随着年龄的增长而加以修改，以便为年轻和老年妇女制定有效的预防办法。 绝经前和绝经后妇女的整个女性生殖道(FRT)都有大量的中性粒细胞 与血液中的中性粒细胞不同。然而，尽管它们位于粘膜表面的关键位置 FRT(妇女感染艾滋病毒的主要部位)及其在先天性免疫中的关键作用，其程度 FRT中性粒细胞对保护妇女免受艾滋病毒感染的作用尚不清楚。国际和平研究所的研究小组 最近发现，人类FRT中的中性粒细胞对HIV的反应是NETsis，这是 防止感染CD4+T细胞。网织红细胞增多症是一种以中性粒细胞释放为特征的现象 胞外陷阱(或Net)，这是与含有抗菌剂的颗粒蛋白相关的DNA片段 活动。研究小组进一步发现，艾滋病毒引起的蚊虫中毒的程度在 绝经后的女性。根据这些初步结果，这里正在测试的假设是艾滋病毒- 诱导的中性粒细胞网状沉着代表了一种以前未被认识到的粘膜天然保护水平 在随着年龄增长而受损的FRT中抗艾滋病毒。这一假设将通过三个具体的 目标。首先，将进行实验研究，以确定FRT网络如何预防艾滋病毒感染(目标1)； 然后，确定艾滋病毒引发FRT中性粒细胞净增多的机制(目标2)；最后， 阐明绝经后妇女中艾滋病毒引起的非接触性网织红细胞增多症为何受损(目标3)。拟议的研究将 研究从FRT不同部位分离的纯化中性粒细胞(子宫内膜、子宫内膜和子宫内膜) 宫颈外)。将使用定量、高通量、延时成像方法对NETsis进行评估。这个 总体目标将是确定NETS如何在FRT中对抗HIV粘膜保护做出贡献。它是 预计这些研究将导致将网织红细胞增多症确定为一种以前未被认识的形式 FRT中针对HIV的免疫保护，这可能会导致我们的 对艾滋病病毒感染的了解。HIV引发蚊虫感染的机制的识别， 以及这些机制如何在老年女性中受到损害，将产生重大的翻译影响，并 为所有年龄段的妇女提供新的预防方法的基础。

PROJECT SUMMARY The main route for HIV acquisition in women of all ages is sexual transmission. While younger women (15–24 years) are at high risk for HIV infection in endemic areas, an increasing incidence of new HIV infections in older women (age >50 years) is observed worldwide. Yet, the mucosal events that lead to the prevention or acquisition of HIV and how mucosal protection is affected with aging are largely unknown. Thus, it is critical to identify the early mucosal mechanisms that prevent HIV infection of target cells and how this protection is modified with aging, in order to develop effective preventive approaches for younger and older women. Neutrophils are abundant throughout the female reproductive tract (FRT) in pre- and post-menopausal women and are distinct from neutrophils present in blood. However, despite their key location at mucosal surfaces in the FRT (the main site for HIV exposure in women) and their critical role in innate immunity, the extent to which FRT neutrophils contribute to protection against HIV infection in women is unknown. The PI’s research group recently discovered that, neutrophils from the human FRT undergo NETosis in response to HIV, which prevents infection of CD4+ T cells. NETosis is a phenomenon characterized by the release of Neutrophil Extracellular Traps (or NETs), which are segments of DNA associated with granular proteins with antimicrobial activity. The research team further found that the magnitude of HIV-induced NETosis is significantly reduced in post-menopausal women. Based on these preliminary results, the hypothesis being tested here is that HIV- induced NETosis of neutrophils represents a previously unrecognized level of mucosal innate protection against HIV in the FRT that is compromised with aging. This hypothesis will be tested through three specific aims. First, experimental studies will be performed to determine how FRT NETs prevent HIV infection (Aim 1); then, to identify the mechanisms by which HIV triggers NETosis of FRT neutrophils (Aim 2); and, finally, to elucidate why HIV-induced NETosis is impaired in post-menopausal women (Aim 3). The proposed studies will investigate purified neutrophils isolated from different sites in the FRT (endometrium, endocervix, and ectocervix). NETosis will be assessed with a quantitative, high-throughput, time-lapse imaging approach. The overall objective will be to determine how NETs contribute to anti-HIV mucosal protection in the FRT. It is expected that these studies will result in the identification of NETosis as a previously unrecognized form of immune protection against HIV in the FRT, one that has the potential of leading to a paradigm shift in our understanding of HIV acquisition. The identification of the mechanisms triggering NETosis in response to HIV, and how these mechanisms are compromised in older women, will have significant translational impact and serve as the foundation for novel prevention approaches for women of all ages.