Control of HIV-1 Transcription by CPSF6 and PP2A

项目总结 根除HIV-1感染的主要障碍是存在一个小的潜伏的 逃脱免疫介导性清除的受感染细胞。由于缺乏转录活性，潜伏期 体内的前病毒不容易被检测到，也不能被自然免疫机制或 分子疗法。因此，了解HIV-1转录是如何调控的将为新的 针对潜在储藏者的治疗策略。 在体内重新激活潜伏库的药理学方法一直被认为是有潜力的 根除疗法已有十多年的历史。然而，这些方法的有效性一直是 令人失望的是，只有少数潜伏感染的细胞似乎对潜伏期反转剂有反应。一个 在我们设计之前，有必要对HIV-1启动子的转录调控有更深入的了解 新颖而有效的LRA。切割和多聚腺苷酸化特异性因子6(CPSF6)是一种细胞蛋白，具有 在细胞生物学和病毒生物学中具有多种功能。我们最近发现CPSF6控制着细胞的稳定性和活性 PP2A是一种直接参与CDK9和RNA Pol II去磷酸化和失活的磷酸酶， 揭示了一条令人兴奋的研究潜在治愈策略的新路线。这项提案将集中在以下几个方面 创新方向：(A)进一步了解艾滋病毒-1转录调控因素，重点是CPSF6 和PP2A；(B)探索使用PP2A抑制作为重新激活潜伏病毒的方法的可能性；以及(3) 基于我们团队最近的一项蛋白质组实验，进一步探索CPSF6的未知功能 产生了几个令人兴奋的点击率。

PROJECT SUMMARY The major barrier toward the eradication of HIV-1 infection is the presence of a small reservoir of latently infected cells that escape immune-mediated clearance. Due to the lack of transcriptional activity, latent proviruses in vivo are not easily detectable and cannot be targeted by either natural immune mechanisms or molecular therapies. Therefore, understanding how HIV-1 transcription is regulated will open doors to novel therapeutic strategies targeting the latent reservoir. Pharmacological approaches to reactivate the latent reservoir in vivo have been considered as potential eradication therapies for more than a decade. However, the effectiveness of these approaches has been disappointing as only a minority of latently infected cells appear to be responsive to latency-reversing agents. A deeper understanding of the transcriptional regulation of the HIV-1 promoter is necessary before we can design novel and effective LRAs. Cleavage and polyadenylation specificity factor 6 (CPSF6) is a cellular protein with multiple functions both in cellular and viral biology. Our recent finding that CPSF6 controls the stability and activity of PP2A, a phosphatase directly implicated in the de-phosphorylation and inactivation of CDK9 and RNA Pol II, reveals an exciting new line of investigation into potential cure strategies. This proposal will focus on the following innovative directions: (a) to further understand the factors regulating HIV-1 transcription, with a focus on CPSF6 and PP2A; (b) to explore the possibility of using PP2A inhibition as a method to reactivate latent viruses; and (3) to further explore the unknown functions of CPSF6 based on a recent proteomics experiment from our group yielding several exciting hits.