New Inhibitors of HIV Replication

描述（由申请人提供）：HIV进入潜伏状态的能力对通过抗逆转录病毒治疗根除HIV-1感染造成了根本性障碍，并促使人们重新关注开发阻断潜伏前病毒重新出现的抑制剂。该研究项目的目标是发现新的抗病毒药物，靶向人类免疫缺陷病毒（HIV）达特蛋白和TAR RNA之间的基本相互作用，这是积极调节HIV-1启动子转录延伸所必需的。Tat-TAR相互作用的抑制剂将能够阻断急性和慢性感染细胞中的病毒复制，并选择性靶向在高活性抗逆转录病毒疗法（HAART）存在下持续存在的缓慢复制病毒的储存库。在上一个资助期间，我们利用基于结构设计的拟肽方法来发现Tat-TAR相互作用的有效抑制剂。所述先导肽模拟物化合物穿透细胞膜，抑制人细胞中Tat依赖性反式激活，并通过Tat依赖性机制抑制多种菌株的原代淋巴细胞中的病毒复制。我们现建议：1.优化达特蛋白的环肽模拟物的活性以抑制细胞提取物中的HIV-1 Tat-TAR相互作用和达特活性2.延伸肽以额外靶向细胞周期蛋白T1与TAR RNA的顶端环的相互作用，从而同时通过两种机制防止Tat-TAR-cycT 1三元复合物的形成和Ptef-b激酶的募集3。优化肽模拟物的摄取和细胞定位，并在基于功能细胞的测定中评估先导化合物的活性4.评价先导化合物在抑制病毒复制方面的活性，并研究在存在拟肽抑制剂的情况下病毒耐药性的出现。该项目将提供指导这些化合物的药理学开发所需的信息。我们非常有信心，在该计划的过程中可以开发出ICSO远低于100 nM的高选择性化合物。

DESCRIPTION (provided by applicant): The ability of HIV to enter a latent state creates a fundamental obstacle to the eradication of HIV-1 infection by anti-retroviral therapy and has prompted renewed interest in developing inhibitors that block the re-emergence of latent proviruses. The goal of this research project is to discover new antiviral drugs that target the essential interaction between the Human Immunodeficiency Virus (HIV) Tat protein and TAR RNA, which is required to positively regulate transcriptional elongation from the HIV-1 promoter. An inhibitor of the Tat-TAR interaction would be able to block viral replication both in acutely and in chronically infected cells and selectively target the reservoir of slowly replicating viruses that persists in the presence of Highly Active Anti Retroviral Therapy (HAART). In the previous funding period, we utilized a peptidomimetic approach grounded in structure-based design to discover potent inhibitors of the Tat-TAR interaction. The lead peptidomimetic compounds penetrate cellular membranes, inhibit Tat-dependent transactivation in human cells and inhibit viral replication in primary lymphocytes for a variety of strains through a Tat-dependent mechanism. We now propose to: 1. Optimize the activity of the cyclic peptide mimetics of the Tat protein to inhibit the HIV-1 Tat-TAR interaction and Tat activity in cell extracts 2. Extend the peptide to additionally target the interaction of cyclin T1 with the apical loop of TAR RNA, thereby preventing formation of the Tat-TAR-cycT1 ternary complex and recruitment of the Ptef-b kinase by two mechanisms simultaneously 3. Optimize the uptake and cellular localization of the peptidomimetics and evaluate the activity of the lead compounds in functional cell-based assays 4. Evaluate the activity of the lead compounds in inhibiting viral replication and study the emergence of resistance in the virus in the presence of the peptidomimetic inhibitors. The project will provide the information required to guide the pharmacological development of these compounds. We are very confident that highly selective compounds with ICSOs well below 100 nM can be developed in the course of this program.