Vif Antagonism: Lead Discovery and SAR - Project 1

项目总结(见说明)： 我们的目标是开发一种针对艾滋病治疗的新的和未开发的靶点的抑制剂。人类免疫缺陷病毒1型(HLV-1)是艾滋病的病原体，是一种复杂的逆转录病毒，编码六种调节蛋白，包括对病毒在体内复制至关重要的Vif。尽管医学取得了显著进步，但HLV-1感染在世界各地继续上升。目前的抗HIV-1药物主要针对HLV-1逆转录酶或蛋白酶。然而，用于靶向这些酶的抑制剂已经产生了病毒耐药性和相关的毒性效应，从而需要针对其他病毒靶点的更有效和毒性更低的治疗方法。HIV-1是一种复杂的逆转录病毒，编码6种调节蛋白，其中Vif是体内病毒复制所必需的。HIV-1 Vif蛋白针对的是一种固有的抗病毒人类DNA编辑酶AP0BEC3G(A3G)，它可以抑制逆转录病毒的复制。由于HIV-1Vif没有已知的细胞同源基因，该蛋白是抗病毒干预的一个极具吸引力但尚未实现的目标。在过去的几年里，我们与Stevenson博士(项目2)和Core B合作，开发并采用了高通量筛选(HTS)分析来识别对抗HIV-1Vif功能的小分子。我们集中精力鉴定了其中一个先导分子RN-18，它只在A3G存在的情况下抑制HLV-1的复制。机制研究表明，RN-18只有在A3G存在的情况下才能促进VIF的降解，增加A3G对病毒粒子的掺入，从而减少病毒的侵染性，并加强病毒基因组的胞苷脱氨基。这些研究首次证明，HIV-1Vif-A3G轴是开发基于小分子的艾滋病新疗法或增强针对病毒的先天免疫的有效靶点。在我们将Vif拮抗剂作为一种新的艾滋病治疗药物开发的初步成功的基础上，我们计划采用高度创新、协作和多学科的方法来实现我们提出的目标。我们的项目有以下具体目标：具体目标1：先导化合物的结构、活性、关系研究和验证。具体目标2：Vif拮抗剂未探索支架的构效关系研究、先导优化和验证。具体目标3：(I)抑制Vif的机制。实验将从分子水平上了解Vif抑制剂的作用机制，(Ii)Vif抑制剂的体内评价。在药理学研究(项目3和核心B)的过程中，我们将测量药物处理动物的血浆和中枢神经系统中的药物浓度。

PROJECT SUMMARY (See instructions): Our goal is to develop inhibitors against a novel and unexploited target for the treatment of AIDS. The human immunodeficiency virus type 1 (HlV-1), the causative agent of AIDS, is a complex retrovirus that encodes six regulatory proteins, including Vif that is essential for viral replication in vivo. Despite remarkable medical advances, HlV-1 infections continue to rise throughout the world. Current anti-HIV-1 agents target mainly HlV-1 reverse transcriptase or protease. However, inhibitors used to target these enzymes have given rise to viral resistance and related toxic effects, creating a need for more potent and less toxic therapies against other viral targets. HIV-1 is a complex retrovirus that encodes 6 regulatory proteins, among which Vif is essential for in vivo viral replication. HIV-1 Vif protein targets an innate antiviral human DNA-editing enzyme, AP0BEC3G (A3G), which inhibits replication of retroviruses. Since HiV-1 Vif has no known cellular homologs, this protein represents an extremely attractive; yet unrealized, target for antiviral intervention. Over the last few years, in collaboration with Dr. Stevenson (Project 2) and Core B, we developed and employed high throughput screening (HTS) assays to identify small molecules that antagonize HIV-1 Vif function. We focused our efforts to characterize one of these lead molecules, RN-18, which inhibits HlV-1 replication only in the presence of A3G. Mechanistic studies revealed that RN-18 enhanced Vif degradation only in the presence of A3G, increased A3G incorporation into virions leading to less infectious viruses, and enhanced cytidine deamination of the viral genome. These studies provide the first evidence that the HIV-1 Vif-A3G axis is a valid target for developing small molecule-based new therapies for AIDS or for enhancing innate immunity against viruses. Based on our preliminary success to develop Vif antagonists as a new class of AIDS therapeutics, we plan to employ highly innovative, collaborative, and multidisciplinary approaches to accomplish our proposed goals. Our project has the following specific aims: Specific Aim 1: Structure activity relationship studies and validation of lead compounds. Specific Aim 2: Structure activity relationship studies, lead optimization, and validation of unexplored scaffolds of Vif antagonists. Specific Aim 3: (i) Mechanism of Vif inhibition. Experiments will be performed to understand the mechanism of Vif inhibitors at molecular level, (ii) In vivo evaluation of Vif inhibitors. During the course of pharmacology studies (Project 3 and core B), we will measure the drug concentrations in plasma and CNS of drug treated animals.