Role of tetherin in HIV-associated thromsosis

 描述（由申请人提供）：联合抗逆转录病毒治疗（cART）的广泛使用已导致人类免疫缺陷病毒（HIV）感染患者的存活率增加。因此，慢性疾病正日益取代急性感染，成为发病和死亡的重要原因。这些慢性疾病之一是动脉粥样硬化血栓形成，其潜在机制尚未完全阐明。在这里，我们证明了来自HIV感染的cART治疗个体的单核细胞和血小板显示宿主限制因子Tetherin BST-2/CD 317水平降低，并且Tetherin损失是通过将健康细胞暴露于病毒蛋白达特和其他细胞来源的炎症介质诱导的， 蛋白酶体依赖机制。我们还表明，单核细胞中含有S3 T4 S5取代突变的抗降解Tetherin的过度表达会导致细胞表面完全形成的微粒（MP）被封存。这些发现将被用来检验HIV通过细胞MP的Tetherin依赖性释放促进血栓形成的总体假设。简而言之，我们将通过采用HIV感染的体外模型（目的1）、HIV相关体内血栓形成的新型小鼠模型（目的2）来检查Tetherin的丢失和MP的相关释放，并前瞻性地确定这些事件如何与接受cART的HIV患者相关联（目的3）。这些研究将汇集四名已建立的研究人员和两名新兴的研究人员，他们在病毒学，血小板/单核细胞生物学，MP，血栓形成和HIV临床研究方面具有公认的专业知识。重要的是，拟议的研究将利用罗切斯特大学艾滋病研究中心（UR-CFAR）提供的研究基础设施。我们的研究具有巨大的临床转化潜力。将在人类受试者中直接测试Tetherin表达的变化，并将其与动脉粥样硬化血栓形成联系起来。因此，揭示HIV和cART调节单核细胞和血小板中微粒产生的机制将提供关键的基础科学基础，以了解这些分子途径如何在哺乳动物细胞中发挥作用，同时深入了解HIV如何触发正在接受或未接受cART的患者的动脉粥样硬化血栓形成事件。总之，我们的提案是以发现为导向的、转化的，并且符合RFA（RFA-HL- 14-024）的目标。

 DESCRIPTION (provided by applicant): Widespread use of combination antiretroviral therapy (cART) has led to increased survival of Human Immunodeficiency Virus (HIV)-infected patients. As a result, chronic diseases are increasingly replacing acute infections as important causes of morbidity and mortality. One of these chronic diseases is atherothrombosis, the underlying mechanisms of which are not fully elucidated. Here, we demonstrate that monocytes and platelets from HIV-infected, cART-treated individuals exhibit reduced levels of the host restriction factor Tetherin BST-2/CD317), and that Tetherin loss is induced by exposure of healthy cells to the viral protein Tat, and to other inflammatory mediators of cellular origin, via proteasome-dependent mechanisms. We also show that over-expression of degradation-resistant Tetherin, which contains a S3T4S5 substitution mutation, in monocytes causes sequestration of fully formed microparticles (MPs) on the cell surface. These findings will be leveraged to test the overall hypothesis that HIV promotes thrombosis via Tetherin-dependent release of cellular MPs. Briefly, we will examine the loss of Tetherin and associated release of MPs by employing in vitro models of HIV infection (Aim 1), novel mouse models of HIV-associated thrombosis in vivo (Aim 2), and prospectively determine how these events are linked in HIV patients receiving cART (Aim 3). These studies will bring together four established investigators and two emerging investigators with proven expertise in virology, platelet/monocyte biology, MPs, thrombosis, and HIV clinical research. Importantly, proposed studies will leverage research infrastructure offered by the University of Rochester Center for AIDS Research (UR-CFAR). Our studies contain great potential for clinical translation. Changes in Tetherin expression will be directly tested in human subjects and linked with atherothrombosis. As such, revealing the mechanisms through which HIV and cART regulate the production of microparticles in monocytes and platelets will provide a critical basic science foundation so as to understand how these molecular pathways function in mammalian cells, while providing insight into how HIV triggers atherothrombotic events in patients who are or are not receiving cART. In summary, our proposal is discovery-oriented, translational, and is responsive to the goals of RFA (RFA-HL- 14-024).