Characterization of Exosomes From Semen of Uninfected and HIV-Infected Men

 描述(申请人提供)：艾滋病毒/艾滋病在人中的持续传播主要是由于性接触受艾滋病毒污染的精液/精浆(SP)所致。SP含有多种促炎因子，可能通过促进细胞因子/趋化因子的产生来促进HIV的传播，这些细胞因子/趋化因子可以招募允许细胞，促进HIV在生殖器上皮细胞的易位，并激活HIV基因的转录。这些因子的水平已被证明在HIV感染过程中发生了变化，HIV感染者的SP中通常有更高水平的各种促炎细胞因子。我们和其他人广泛研究了SP成分的性质，包括它们促进艾滋病毒感染的能力和它们创造有利于艾滋病毒复制的炎症状态的能力。然而，SP中的一类因子很少受到关注，即胞外体，即通常在一次射精中存在数万亿个胞外小泡。外切体是 重要的细胞间信号转导，并诱导各种炎症或免疫调节反应。尽管许多研究已经确定了来自未感染和HIV感染个体的血浆来源的外切体，但很少有人了解精液外切体与HIV传播之间的关系。在这个R21中，我们测试了一些假设，即HIV感染会改变SP中外切体的组成，以及HIV感染者的SP外切体可以诱导炎症并促进对HIV感染的易感性。我们将通过在目标1中评估HIV感染和ART治疗状态如何影响SP中外切体的数量、组成和RNA载量来实现这一点。然后，在目标2中，我们将直接测试来自HIV感染男性的Exosome是否有助于SP诱导生殖器粘膜内细胞的炎症，以及这些Exosome是否可以增加允许细胞对HIV感染的易感性。这些研究将首次对感染HIV的男性的SP外切体进行表征，并将有助于更好地了解这些小泡如何影响HIV性传播的早期事件。

 DESCRIPTION (provided by applicant): The continuing spread of HIV/AIDS in people is predominantly fueled by sexual exposure to HIV-contaminated semen/seminal plasma (SP). SP harbors a variety of pro-inflammatory factors that may facilitate HIV transmission by promoting the production of cytokines/chemokines that recruit permissive cells, enhance the translocation of HIV across the genital epithelium, and activate HIV gene transcription. The levels of these factors have been shown to be altered during HIV infection, with HIV-infected individuals generally harboring higher levels of various pro-inflammatory cytokines in SP. We and others have extensively studied the properties of SP constituents, both with regards to their ability to promote HIV infection and their ability to create an inflammatory state favoring HIV replication. However, one class of factors in SP that has received little attention is exosomes, small extracellular vesicles of which trillions are typically present in a single ejaculate. Exosomes are important intercellular signal transducers and induce various inflammatory or immunomodulatory responses. Although numerous studies have characterized plasma-derived exosomes from both uninfected and HIV-infected individuals, very little has been done to understand the relationship between semen exosomes and HIV transmission. In this R21, we test the hypotheses that HIV infection alters the composition of exosomes in SP and that SP exosomes from HIV-infected men can induce inflammation and promote susceptibility to HIV infection. We will accomplish this by assessing in Aim 1 how HIV infection and ART treatment status affect the quantity, composition, and RNA cargo of exosomes in SP. Then in Aim 2, we will directly test the whether exosomes from HIV-infected men contribute towards the ability of SP to induce inflammation in cells lining the genital mucosa, and whether these exosomes can increase the susceptibility of permissive cells to HIV infection. These studies will be the first t characterize SP exosomes from HIV-infected men, and will lead to a better understanding of how these vesicles affect the early events of sexual transmission of HIV.