Identification and characterization of novel anti-HIV inhibitors

描述(申请人提供)：人胞苷脱氨酶APOBEC3(A3)蛋白是针对HIV的有效宿主防御。这些抗病毒蛋白在新合成的负链病毒DNA中诱导胞嘧啶到尿嘧啶的致死性修饰，导致流产的病毒感染。艾滋病毒必须克服这些宿主细胞防御才能成功复制病毒。HIV-1编码一种名为Vif的蛋白质，它通过26S蛋白酶体靶向降解A3蛋白来抑制它们的抗病毒作用。VIF劫持细胞Cullin5(Cul5)、ElonginB和ElonginC，形成针对A3G的病毒E3泛素连接酶，以实现多泛素化和降解。因此，确定新的策略来保存A3的抗病毒功能是抗逆转录病毒治疗的一个令人兴奋的新目标。在这一应用中，我们建议利用我们在HIV-1 Vif/A3系统方面的专业知识和我们对病毒逃避机制的新理解，建立一种基于细胞的快速检测Vif小分子抑制剂的方法，并进一步优化和调整该系统，以应用于高通量分子筛选大分子文库，以识别抑制HIV-1复制的分子。在我们的初步筛选中，我们还将确定几种小分子化合物的特性，这些化合物已被确定为抑制Vif介导的A3G降解。 公共卫生相关性：HIV-1病毒感染性因子(VIF)是HIV-1在天然靶细胞(如表达先天抗病毒人APOBEC3G(A3G)和相关胞苷脱氨酶的CD4+T细胞和巨噬细胞)中复制所必需的调节蛋白。我们已经确定了一种VIF的小分子抑制剂。本项目的总体目标是建立一种基于细胞的快速鉴定Vif小分子抑制剂的方法，并进一步优化和调整该系统，以应用于大分子文库的高通量分子筛选，以识别抑制HIV-1复制的分子。

DESCRIPTION (provided by applicant): Human cytidine deaminases APOBEC3 (A3) proteins are potent host defenses against HIV. These antiviral proteins induce lethal modification of cytosines to uracils in newly synthesized minus-strand viral DNA, resulting in abortive viral infection. HIV must overcome these host cellular defenses for successful viral replication. HIV-1 encodes a protein, Vif, which suppresses the antiviral effects of A3 proteins by targeting them for degradation through the 26S proteasome. Vif hijacks cellular Cullin5 (Cul5), ElonginB, and ElonginC to form a viral E3 ubiquitin ligase that targets A3G for polyubiquitination and degradation. Thus, identification of novel strategies to preserve the antiviral functions of A3 is an exciting new target for antiretroviral therapy. In this application, we propose to capitalize our expertise in HIV-1 Vif/A3 system and our new understanding of the viral evasion mechanism to develop a rapid cell-based assay for the identification of small molecule inhibitors of Vif and to further optimize and adapt the system for application to high throughput molecular screening of large compound libraries to identify molecules that inhibit HIV-1 replication. We will also characterize several small molecule compounds that have been identified to inhibit Vif mediated A3G degradation in our initial screening. PUBLIC HEALTH RELEVANCE: The HIV-1 virion infectivity factor (Vif) is an essential regulatory protein required for HIV- 1 replication in natural target cells such as CD4+ T-cells and macrophages which express innate antiviral human APOBEC3G (A3G) and related cytidine deaminases. We have identified a small molecule inhibitor of Vif. The overall goal of this project is to develop a rapid cell-based assay for the identification of small molecule inhibitors of Vif and to further optimize and adapt the system for application to high throughput molecular screening of large compound libraries to identify molecules that inhibit HIV-1 replication.