CD8 T cell suppression of HIV latency establishment and maintenance in virally suppressed individuals

摘要： 目前的抗逆转录病毒疗法（ART）并不能根除艾滋病毒，这一点可以从病毒血症在感染后的快速反弹中看出。 治疗中断。通过称为Latency的化合物拯救潜伏感染细胞中的病毒基因表达 逆转剂（LRA）是一种减少ART治疗的HIV感染个体中病毒库的策略（即， Shock & Kill）。HIV潜伏期由导致病毒表达沉默的机制触发，包括 通过组蛋白甲基化和去乙酰化进行的表观遗传DNA修饰， 转录因子和新生病毒转录物的低效延伸。ART治疗SIV的最新研究- 感染的猕猴表明，CD 8+淋巴细胞的耗竭之后是病毒的再活化， 产生，并增加对IL-15超激动剂ALT 803的LRA作用的易感性。这些结果 强烈表明CD 8+淋巴细胞在沉默HIV表达中起重要但未充分研究作用。 在这个建议中，我们假设CD 8 + T细胞通过促进HIV基因的表达来抑制HIV基因的表达。 建立和维持HIV潜伏期，逆转这种作用可能导致显著 放大各种化合物的LRA效应，从而影响体内储库尺寸和稳定性。我们 将使用创新的方法来确定CD 8 + T细胞介导的HIV沉默机制。目标1： 将采用一种新的HIV潜伏期模型来描述CD 8 + T细胞在HIV建立中的作用， 延迟。我们将量化HIV基因在CD 4 + T细胞亚群中的表达，并描述CD 8 + T细胞亚群对HIV基因表达的影响。 HIV潜伏期的建立。在目标2中，我们将描述CD 8 + T细胞在维持免疫应答中的作用。 艾滋病毒潜伏期。我们的体外模型将使我们能够定义CD 8 + T细胞如何在细胞因子作用期间维持HIV潜伏期。 驱动活化、增殖或分化。在目标3中，我们将设计一个组合抗延迟策略， 将消除大多数（如果不是全部）潜伏感染细胞。我们将采用高维流式细胞术来确定 与潜伏期逆转的抑制和激活相关的表型改变。最终，我们将 表征CD 8+淋巴细胞在对抗特异性LRA（和LRA）的潜伏期逆转中的作用 组合）作为开发有效干预措施的关键步骤，其中潜伏感染细胞中的病毒转录 被拯救以减小水库的大小。本提案中描述的实验将确定新的机制 艾滋病毒沉默，可导致重新激活和随后消除大多数（如果不是全部）潜伏感染 细胞我们建议，这一总体目标可以通过逐步科学的方法来实现， 包括体外和离体研究，将解决一个新定义的艾滋病毒持久性的机制。我们认为 本申请中提出的工作将使我们能够理解CD 8+细胞的机制， 淋巴细胞抑制病毒转录并最终促进ART治疗的HIV潜伏期和持久性。 艾滋病毒感染者，从而帮助设计新的方法来消除艾滋病毒。

ABSTRACT: Current antiretroviral therapy (ART) does not eradicate HIV as shown by the rapid rebound of viremia upon treatment interruption. Rescuing viral gene expression in latently infected cells by compounds termed Latency Reversing Agents (LRA) is a strategy to reduce the virus reservoir in ART-treated HIV-infected individuals (i.e., shock & kill). HIV latency is triggered by mechanisms that lead to the silencing of virus expression including epigenetic DNA modification through histone methylation and deacetylation, limited availability of critical transcription factors and inefficient elongation of the nascent viral transcripts. Recent studies in ART-treated SIV- infected macaques demonstrated that depletion of CD8+ lymphocytes is followed by reactivation of virus production, and increased susceptibility to the LRA effect of the IL-15 superagonist ALT803. These results strongly suggest that CD8+ lymphocyte play an important yet understudied role in silencing HIV expression. In this proposal, we hypothesize that CD8+ T cells suppress HIV gene expression by promoting the establishment and maintenance of HIV latency, and that reversal of this effect may result in a significant amplification of the LRA effect of various compounds, thus impacting the reservoir size and stability in vivo. We will use innovative approaches to identify the CD8+ T cell mediated mechanisms of HIV silencing. In Aim 1, we will employ a novel model of HIV latency to characterize the role of CD8+ T cells in the establishment of HIV latency. We will quantify HIV gene expression in CD4+ T cell subsets and characterize the impact of CD8+ T cells on HIV latency establishment. In Aim 2, we will characterize the role of CD8+ T cells in the maintenance of HIV latency. Our in vitro model will allow us to define how CD8+ T cells maintain HIV latency during cytokine driven activation, proliferation or differentiation. In Aim 3, we will design a combinatorial anti-latency strategy that will eliminate most if not all latently infected cells. We will employ high dimensional flow cytometry to define alterations in phenotype associated with suppression and activation of latency reversal. Ultimately, we will characterize the role of CD8+ lymphocyte in counter-acting the latency reversal by specific LRAs (and LRA combinations) as a key step to develop effective interventions in which viral transcription in latently infected cells is rescued to reduce the reservoir size. The experiments described in this proposal will identify novel mechanisms of HIV silencing that can lead to the reactivation and subsequent elimination of most (if not all) latently infected cells. We propose that this overarching goal can be achieved through a step-wise scientific approach that includes in vitro and ex vivo studies that will address a newly-defined mechanism of HIV persistence. We believe that the work proposed in this application will allow us to understand the mechanisms by which CD8+ lymphocytes suppress virus transcription and ultimately promote HIV latency and persistence in ART-treated HIV-infected individuals, thus helping designing new approaches for HIV eradication.