Epigenetic Control of CD8 T-Cell Differentiation in Human Lymph Nodes

项目总结 强有力的抗逆转录病毒疗法的发展，现在以每天一片的形式提供，已经改变了 将艾滋病毒感染转化为慢性病。在全球范围内，目前有1900多万人正在接受终身治疗和检测- 与治疗策略一样，口服PrEP也有能力进一步减少艾滋病毒的传播。然而， 尽管有这些显著的进展，延长的ART介导的血浆病毒载量被抑制到无法检测到 病毒水平并不能根除病毒，一旦治疗中断，病毒就会迅速反弹。众多后勤保障 向艾滋病毒携带者提供终身护理所带来的限制和成本挑战凸显了需要 在缺乏治疗的情况下控制病毒的新策略。新出现的数据表明，淋巴结 是抗逆转录病毒治疗期间HIV持续存在的主要来源，主要是因为受感染的T滤泡辅助细胞受到保护 由于生发中心(GC)部分排斥细胞毒性CD8 T细胞(CTL)而导致免疫消除。这个 调控CXCR5表达从而允许CTL迁移到GC的分子机制尚不清楚， 这主要是由于为这类研究获取淋巴结样本的困难。通过创新 招聘策略，我们现在已经解决了这个问题。我们建议使用储存的淋巴结样本 从血浆病毒血症开始时确诊和治疗的人那里获得的，在许多情况下，当血浆病毒载量时 低于1,000个RNA拷贝/毫升，以调查为什么CTL在很大程度上被排除在GC之外。我们的预赛 ATAC-Seq研究表明，CXCR5在淋巴结CTL上的表达受表观遗传调控。追随 根据这一观察结果，我们建议进行染色质可及性分析和转录图谱 对HIV特异性CD8 T细胞进行分类，以确定调节CXCR5表达的表观遗传机制。我们的 实验方法将涉及成对染色质可及性和分类卵泡的转录分析 卵泡外HIV特异性CD8T细胞。这一策略将有助于识别新的表观遗传和转录 两个群体之间不同的因素。最后，我们将处理一些不同的 使用外源因子即细胞因子和表观遗传修饰药物来确定表达的基因 诱导CD8 T细胞表达CXCR5的最佳条件我们的结果将导致新的战略 将CTL重定向到滤泡区，在那里它们需要杀死感染艾滋病毒的细胞。如果成功，我们的研究将 导致将CTL重定向到滤泡区以根除艾滋病毒感染的新战略，作为治疗战略的一部分。

PROJECT SUMMARY The development of potent antiretroviral therapies, now delivered as a single pill once a day, has transformed HIV infection into a chronic disease. Globally, over 19 million people are now on life-long treatment, and test- and-treat strategies as was well as oral PrEP have the ability to further reduce HIV transmissions. However, despite these remarkable advances, prolonged ART mediated suppression of plasma viral loads to undetectable levels does not eradicate the virus, which rapidly rebounds upon treatment interruption. The many logistical limitations and cost challenges that come with providing life-long care to those living with HIV highlights the need for novel strategies of controlling the virus in the absence of therapy. Emerging data indicate that lymph nodes are a major source of HIV persistence during ART mainly because infected T follicular helper cells are protected from immune elimination due to partial exclusion of cytotoxic CD8 T cells (CTL) from germinal centers (GC). The molecular mechanisms that regulate CXCR5 expression which allows CTL migration into GCs are not known, mainly due to the difficulty associated with obtaining lymph node samples for such studies. Through innovative recruitment strategies, we have now solved this problem. We propose to use stored lymph node samples obtained from persons identified and treated at the onset of plasma viremia, in many when plasma viral loads are less than 1,000 RNA copies/ml to investigate why CTLs are largely excluded from GCs. Our preliminary ATAC-Seq studies suggest that CXCR5 expression on lymph node CTLs is epigenetically regulated. To follow up on this observation we propose to conduct chromatin accessibility analysis and transcriptional profiling of sorted HIV-specific CD8 T cells to identify epigenetic mechanisms that regulate CXCR5 expression. Our experimental approach will involve pairwise chromatin accessibility and transcription analysis of sorted follicular and extrafollicular HIV-specific CD8 T cells. This strategy will help to identify novel epigenetic and transcription factors that are different between the two populations. Finally, we will manipulate some of the differentially expressed genes using exogenous agents namely cytokines and epigenetic modifying drugs to determine the optimal conditions to induce CXCR5 expression on CD8 T cells. Our results will lead to novel strategies for redirecting CTL to follicular areas where they are needed to kill HIV infected cells. If successful, our studies will lead to novel strategies for redirecting CTL to follicular areas to eradicate HIV infection as part of a cure strategy.