Determining the mechanisms of vascular CD8 T cell activation in CMV and HIV infections

项目总结/摘要 接受抗逆转录病毒治疗的艾滋病毒感染者（PWH）更早地死于许多 同样的并发症困扰着未感染艾滋病毒的老年人。PWH的CVD风险升高至少部分是由于 持续增加的炎症和CD 8 T细胞和单核细胞的活化， 和表征了很多长者及几乎所有威尔斯亲王医院都同时感染巨细胞病毒， 显示与PWH中的炎症和CD 8 T细胞的急剧扩增相关，并且已经被证实 与CVD独立相关。活化的CD 8 T细胞在体内内皮功能障碍的部位积聚， 在动物模型中促进动脉粥样硬化性CVD（ASCVD），并可触发促动脉粥样硬化表型， 体外单核细胞--浸润血管的CD 8 T细胞是否识别同源抗原肽 从未在体内明确显示，也没有抗原非特异性激活途径被严格证实。 评估。在这个建议中，我们试图确定CMV和活化的T细胞如何合谋加剧CVD 除了传统的风险因素，在艾滋病毒未感染者，并了解是否和如何激活T细胞进一步 增加PWH合并CMV感染的CVD风险。我们假设，体内活跃的CMV复制 动脉粥样硬化病变为浸润的CMV反应性T细胞提供抗原， 非特异性信号（包括IL-15和CD 2/LFA-3轴）进一步塑造T细胞应答。我们建议 这些信号在未感染HIV的人群中加重ASCVD，在感染HIV的人群中进一步升高 感染我们将测试这些假设与以下具体目标：目标1：定义的机制， 体内斑块CD 8 T细胞活化。我们将使用批量和单细胞RNA测序结合条形码- 抗体和多聚体标记，以检验CD 8 T细胞从动脉粥样硬化斑块中恢复的假设。 CMV+供体比CMV-供体的斑块CD 8 T细胞表现出更强的促炎性转录程序 捐赠者，我们将确定相关的激活途径。然后我们将使用免疫荧光成像， 荧光原位杂交以确认与激活信号如IL-15，LFA-3， 和CMV。目的2：探讨HIV感染对血管内皮细胞的激活和原位定位的影响 CD 8 T细胞。我们将使用RNA测序来识别和表征激活和抗原的机制， 血管CD 8 T细胞的特异性。我们还将使用免疫荧光成像来检验假设， 来自PWH的血栓会增加激活信号和额外的促炎因子， 与年龄和性别匹配的对照组相比，我们的研究将确定 由此慢性病毒感染驱动CD 8 T细胞介导的血管病变， 超越传统的风险因素，以预防/治疗PWH和未感染HIV的老年人的ASCVD。

PROJECT SUMMARY/ABSTRACT Persons living with HIV infection (PWH) on antiretroviral therapy (ART) are succumbing earlier to many of the same complications that plague the HIV-uninfected elderly. This elevated CVD risk in PWH is at least partly due to persistently increased inflammation and activation of CD8 T cells and monocytes that our group has identified and characterized. Many elderly and nearly all PWH are coinfected with cytomegalovirus (CMV), which we have shown is associated with inflammation and dramatic expansion of CD8 T cells in PWH, and has been independently linked to CVD. Activated CD8 T cells accumulate at sites of endothelial dysfunction in vivo, promote atherosclerotic CVD (ASCVD) in animal models, and can trigger a proatherogenic phenotype on monocytes in vitro – yet whether CD8 T cells infiltrating the vasculature recognize cognate antigenic peptides has never been definitively shown in vivo, nor have antigen-nonspecific activating pathways been rigorously evaluated. In this proposal, we seek to identify how CMV and activated T cells conspire to exacerbate CVD beyond traditional risk factors in HIV-uninfected persons, and to understand if and how activated T cells further promote CVD risk in PWH with CMV coinfection. We hypothesize that active CMV replication within atherosclerotic lesions provides antigen for infiltrating CMV-reactive T cells and that additional antigen- nonspecific signals (including IL-15 and the CD2/LFA-3 axis) further shape the T cell response. We propose that these signals exacerbate ASCVD in HIV-uninfected persons and that they are further elevated in those with HIV infection. We will test these hypotheses with the following specific aims: Aim 1: To define the mechanisms of plaque CD8 T cell activation in vivo. We will use bulk and single cell RNA-sequencing coupled with barcoded- antibody and multimer labeling to test the hypothesis that CD8 T cells recovered from atherosclerotic plaques of CMV+ donors exhibit a more proinflammatory transcriptional program than plaque CD8 T cells from CMV- donors, and we will identify the activating pathways involved. We will then use immunofluorescence imaging and fluorescence in situ hybridization to confirm spatial relationships with activating signals such as IL-15, LFA-3, and CMV. Aim 2: To define the effect of HIV infection on the activation and in situ localization of vascular CD8 T cells. We will use RNA-sequencing to identify and characterize the mechanisms of activation and antigen- specificity of vascular CD8 T cells. We will also use immunofluorescence imaging to test the hypothesis that aortas from PWH will have increased activating signals and additional pro-inflammatory factors that bolster T cell activation compared to aortas from age- and gender-matched controls. Our studies will define mechanisms whereby chronic viral infection drives CD8 T cell-mediated vascular pathology and may identify novel targets beyond traditional risk factors to prevent/treat ASCVD in PWH and the HIV-uninfected elderly.