Regulatuion of HIV-1 Gene Expression in Latency by YY1, RuvB2, and ZAP

描述(申请人提供)：通过高效抗逆转录病毒疗法(HAART)，HIV-1复制可以被控制，以保持血浆中病毒RNA水平低于常规方法检测的水平。然而，记忆中的CD4+T细胞中持续存在沉默的HIV-1前病毒DNA是艾滋病患者根除该病毒的主要障碍。已有多种机制被报道，通过这些机制，HIV-1前病毒在这些细胞中保持沉默状态。病毒活跃复制的主要障碍被认为是在转录水平上。然而，在长期接受HAART治疗的患者中，可以通过敏感的检测方法检测到病毒RNA，这表明转录控制可能不是维持病毒潜伏期的唯一机制。这个项目现在的目标是了解三个调控系统对HIV-1基因表达的转录后控制：无意义介导的衰退(NMD)系统；我们最近发现的HIV翻译抑制因子(RVB2)；以及锌指抗病毒蛋白(ZAP)，它沉默并触发许多病毒RNA的降解。我们将具体探讨这些系统中的每一个在维持HIV-1潜伏期方面的可能作用。我们将检测HIV-1感染患者的CD4阳性记忆T细胞中HIV-1RNA和蛋白质的表达水平，在使用siRNA敲除技术操纵这些调控系统的每个功能后。控制HIV-1基因转录后表达调控的主要机制的发现是释放抑制和激活病毒复制的重要第一步。这种激活将允许通过免疫系统检测感染病毒的细胞，并通过针对记忆T细胞内和表面表达的病毒蛋白的治疗来清除感染细胞。

DESCRIPTION (provided by applicant): With Highly Active AntiRetroviral Therapy (HAART), HIV-1 replication can be controlled to maintain a plasma level of viral RNA below detection by conventional means. However, the continued presence of silent HIV-1 proviral DNA in memory CD4+ T cells is a major barrier to the eradication of the virus in AIDS patients. Multiple mechanisms have been reported by which HIV-1 proviruses are maintained in a silent state in these cells. The major block to active viral replication is believed to be at the transcriptional level. However, viral RNAs can be detected in long-term HAART-treated patients by sensitive detection methods, suggesting that transcriptional control may not be the only mechanism underlying the maintenance of viral latency. This project now aims to understand the post-transcriptional control of HIV-1 gene expression mediated by three regulatory systems: the Nonsense Mediated Decay (NMD) system; a repressor of HIV translation (RVB2) which we have recently identified; and the Zinc- finger Antiviral Protein (ZAP) which silences and triggers degradation of many viral RNAs. We will specifically explore the possible role of each of these systems in the maintenance of HIV-1 latency. We will examine the levels of HIV-1 RNA and protein expression in CD4-positive memory T cells from HIV-1 infected patients after manipulating the functions of each of these regulatory systems using siRNA knockdown technology. Discovery of the major mechanisms controlling post-transcriptional regulation of HIV-1 gene expression is an essential first step toward the release of repression and the activation of viral replication. This activation will permit the detection of virus-infected cells y the immune system and facilitate the clearance of infected cells by therapies that target viral proteins expressed in and on the surface of memory T cells.