Elimination of persistently HIV-infected cells by targeting host factors

HIV-1的治愈现在似乎是可以实现的，本研究的主要目的是通过确定新的策略来消除持续感染的细胞或防止细胞的持续/潜伏感染，从而有助于治愈。HIV在宿主细胞（CD4+ T细胞和巨噬细胞）中的持续存在是治愈的主要障碍，因为目前的治疗方法只针对病毒复制，留下了一个持续感染的细胞库，只要这些细胞存活，这些细胞就会携带HIV基因组。我们将重点关注HIV感染的巨噬细胞作为持续HIV感染的储存库的作用，以及作为引起CD4+ T细胞潜伏感染的关键角色。为了实现我们的目标，我们将追求三个相互关联的目标。每个目标都将侧重于消除HIV感染的巨噬细胞或防止HIV感染的巨噬细胞在CD4+ T细胞中驱动HIV潜伏期的独特策略。目的1将研究两个基因/蛋白USP18和ISG15在HIV出芽中的作用。出芽是HIV离开被感染细胞的机制，是由宿主和病毒蛋白控制的。我们提出了USP18在允许HIV出芽发生中的新作用。我们预测，破坏USP18活性将阻止HIV出芽，导致细胞内促凋亡病毒蛋白的积累，这单独或与其他策略结合将导致感染巨噬细胞死亡。我们将使用shrna的过表达或基因沉默来确定USP18在HIV感染巨噬细胞的HIV出芽和存活中的作用。巨噬细胞通过蛋白酶体或溶酶体途径有效地降解和回收细胞内蛋白质。结合被破坏的HIV出芽，我们将抑制蛋白质再循环以增强HIV蛋白质的积累，从而增加细胞毒性细胞的死亡。目的2将研究细胞基因/蛋白如何调节巨噬细胞中HIV的复制速率。通过确定抑制或增强HIV基因表达、蛋白质翻译或出芽的因素，我们将确定可以用来杀死HIV感染巨噬细胞的其他脆弱性。当与预防HIV出芽和/或HIV蛋白再循环的策略配对时，增强的HIV复制将增加细胞应激，导致HIV感染的巨噬细胞死亡。目的3将研究hiv感染的巨噬细胞在驱动CD4+ T细胞潜伏感染中的作用。我们已经确定了hiv感染巨噬细胞的独特表型变化，包括可能支持CD4+ T细胞潜伏感染的特定结果。潜伏的两种途径将被研究，包括导致HIV感染的CD4+ T细胞生长停滞的机制和增强静止CD4+ T细胞的HIV感染的机制。这三个目标共同提供了一种全面的策略来识别/利用HIV感染巨噬细胞的独特特性来破坏持续/潜伏感染的生物学途径。

DESCRIPTION: A cure for HIV-1 now seems achievable and the primary objective of this study is to contribute to a cure by identifying novel strategies to eliminate persistently-infected cellsor prevent persistent/latent infection of cells. HIV persistence in host cells (CD4+ T cells and macrophages) is a major obstacle to a cure because current therapies only target viral replication, leaving a reservoir of persistently-infected cells that carry the HIV genome for as long as those cells survive. We will focus on the role of HIV-infected macrophages as a reservoir for persistent HIV infection and as a key player in causing latent infection of CD4+ T cells. To achieve our goal, we will pursue three interrelated aims. Each aim will focus on unique strategies to either eliminate HIV-infected macrophages or prevent HIV-infected macrophages from driving HIV latency in CD4+ T cells. Aim 1 will investigate the role of two genes/proteins, USP18 and ISG15, in HIV budding. Budding, the mechanism by which HIV leaves an infected cell, is controlled by host and viral proteins. We propose a novel role for USP18 in allowing HIV budding to occur. We predict that disruption of USP18 activity will prevent HIV budding leading to accumulation of intracellular pro-apoptotic viral proteins, which alone or in combination with other strategies will cause death of infected macrophages. We will use over-expression or gene silencing with shRNAs to determine the role of USP18 in HIV budding and survival of HIV-infected macrophages. Macrophages efficiently degrade and recycle intracellular proteins through proteasome or lysosome pathways. In conjunction with disrupted HIV budding, we will inhibit protein recycling to enhance accumulation of HIV proteins to increase cytotoxic cell death. Aim 2 will investigate how cellular genes/proteins regulate the rate of HIV replication in macrophages. By identifying factors that inhibit or enhance HIV gene expression, protein translation or budding, we will identify additional vulnerabilities that can be exploited to kill HV-infected macrophages. When paired with a strategy to prevent HIV budding and/or HIV protein recycling, enhanced HIV replication will augment cell stress leading to death of HIV-infected macrophages. Aim 3 will study the role of HIV-infected macrophages in driving latent infection of CD4+ T cells. We have identified unique phenotypic changes to HIV-infected macrophages that include specific outcomes likely to support latent infection of CD4+ T cells. Two pathways of latency will be studied including a mechanism to cause growth arrest of HIV-infected CD4+ T cells and a mechanism to enhance HIV infection of resting CD4+ T cells. Together these three aims provide a comprehensive strategy to identify/exploit unique properties of HIV- infected macrophages to disrupt biological pathways of persistent/latent infection.