Aging compromises neutrophil-mediated innate protection against HIV in the human female genital tract.

项目摘要 所有年龄妇女感染艾滋病毒的主要途径是性传播。而年轻妇女（15-24岁） 在流行地区，艾滋病毒感染的高风险人群中，老年人新感染艾滋病毒的发病率增加， 妇女（年龄>50岁）在全世界都有。然而，导致预防或获得的粘膜事件 以及粘膜保护是如何随着年龄的增长而受到影响的，在很大程度上是未知的。因此，确定 预防HIV感染靶细胞的早期粘膜机制，以及这种保护作用如何通过 老龄化，以便为年轻和老年妇女制定有效的预防方法。 中性粒细胞在绝经前后的女性生殖道（FRT）中大量存在 并且与血液中存在的嗜中性粒细胞不同。然而，尽管它们的关键位置在粘膜表面， FRT（女性艾滋病毒暴露的主要部位）及其在先天免疫中的关键作用， 中性粒细胞有助于保护妇女免受艾滋病毒感染是未知的。PI的研究小组最近 发现，来自人类FRT的中性粒细胞在对HIV的反应中发生NETosis，从而防止感染 CD 4 + T细胞NETosis是一种现象，其特征在于释放神经细胞外陷阱（或 NET），其是与具有抗微生物活性的颗粒蛋白相关的DNA片段。研究 研究小组进一步发现，在绝经后， 妇女基于这些初步结果，这里正在测试的假设是， 嗜中性粒细胞代表了FRT中一种以前未被认识到的粘膜抗HIV先天保护水平， 会随着年龄的增长而受损这一假设将通过三个具体目标进行检验。第一，实验研究 将进行，以确定如何FRT NET预防艾滋病毒感染（目标1），然后，以确定机制 HIV触发FRT中性粒细胞NETosis的机制（目的2）;最后，阐明为什么HIV诱导的NETosis 绝经后妇女中受损（目标3）。 拟议的研究将调查从FRT中不同部位分离的纯化中性粒细胞（子宫内膜， 子宫颈内膜和子宫颈外膜）。NETosis将通过定量、高通量、延时成像进行评估 approach.总体目标是确定NET如何有助于抗HIV粘膜保护， FRT。预计这些研究将导致NETosis作为一种以前未被认识到的 FRT中针对HIV的免疫保护形式，有可能导致 我们对艾滋病毒感染的理解识别响应于以下事件而触发NETosis的机制： 艾滋病毒以及这些机制如何在老年女性中受到损害，将产生重大的转化影响， 作为所有年龄妇女的新型预防方法的基础。

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.