Novel Stimulators of HIV-1 Integrase for Use in Combination Microbicide Regimens

描述（由申请人提供）：该项目的长期目标是开发干扰HIV复制和传播的方法，这将对预防HIV/AIDS的传播产生重大影响。任何成功的预防战略都必须在感染确立之前发挥作用，而确立的逆转录病毒感染的特点是融合。病毒整合酶在体内催化至少两种核酸内切酶反应：特异性切口以制备用于整合的病毒DNA末端和将病毒DNA非特异性插入细胞DNA中。整合酶还具有有效的非特异性核酸内切酶活性，可以在体外切割任何DNA序列，并且这种活性被某些小化合物显着刺激。这些事实表明了一种新的（具有讽刺意味的）抗病毒策略，其中整合酶在整合前被刺激破坏病毒DNA（对细胞DNA的任何损伤仅限于新感染的细胞，并阻断感染）。因此，本提案的目的是确定HIV-1整合酶的非特异性切口活性的有效刺激物，并使这些试剂中的至少一种接近临床测试。基于已知的先例和初步数据，中心假设是整合酶的非特异性核酸内切酶活性可以被刺激用于新的抗病毒策略，该策略可以是安全有效的组合杀微生物剂方案的一部分。在R21阶段，Aim 1将优化整合酶介导的非特异性DNA切口的高通量测定; Aim 2将在宾夕法尼亚州立大学药物开发和发现核心中筛选50，000种化学物质，以寻找刺激HIV-1整合酶非特异性切口DNA的其他试剂（通过适当的二次测定来验证阳性命中）; Aim 3将使用定量抗病毒和细胞毒性研究，根据其治疗指数优先考虑整合酶刺激剂（IS）化合物，所有这些都将反馈给有机化学家，他们将设计和合成先导化合物的合理类似物，以迭代的方式进行测试。在R33阶段，目标4将在扩大的毒性研究中测试每种候选IS化合物的安全性，包括宫颈阴道毒性的小鼠模型;目标5将测试针对HIV-1不同亚型和HIV-1感染的NOD-SCID-hu小鼠模型的抗病毒活性范围。这些数据也将反馈到发现途径，以制造IS化合物的新衍生物。最后，由于理想的杀微生物剂方案将结合联合收割机药剂，这些药剂在细胞外起作用以阻止病毒进入细胞内，而这些药剂在细胞内起作用以终止任何进入细胞的病毒的感染，因此Aim 6将评估包括IS化合物的杀微生物剂组合对HIV-1的协同活性，为将至少一种候选药物转移到未来的临床试验做准备。

DESCRIPTION (provided by applicant): The long-term goal of this project is to develop ways to interfere with HIV replication and transmission, which would have major implications for preventing the spread of HIV/AIDS. Any successful preventive strategy must work before infection becomes established, and the hallmark of an established retroviral infection is integration. The viral integrase enzyme catalyzes at least two endonuclease reactions in vivo: specific nicking to prepare the ends of viral DNA for integration and nonspecific insertion of the viral DNA into cellular DNA. Integrase also has a potent nonspecific endonuclease activity that can nick any DNA sequence in vitro, and this activity is dramatically stimulated by certain small compounds. These facts suggest a novel (and ironic) antiviral strategy in which integrase is stimulated to destroy viral DNA before integration (with any damage to cellular DNA being limited to newly infected cells and also blocking infection). Thus, the objectives of this proposal are to identify potent stimulators of the nonspecific nicking activity of HIV-1 integrase and to bring at least one of these agents to the verge of clinical testing. The central hypothesis, based on known precedents and preliminary data, is that integrase's nonspecific endonuclease activity can be stimulated for a new antiviral strategy that can be part of a safe and effective combination microbicide regimen. In the R21 phase, Aim 1 will optimize a high-throughput assay for integrase-mediated nonspecific DNA nicking; Aim 2 will screen 50,000 chemicals in the Penn State Drug Development and Discovery Core for additional agents that stimulate HIV-1 integrase to nick DNA nonspecifically (with appropriate secondary assays to validate positive hits); and Aim 3 will use quantitative antiviral and cell toxicity studies to prioritize integrase stimulator (IS) compounds based on their therapeutic indices, all the while feeding back to organic chemists who will design and synthesize rational analogues of lead compounds for testing in an iterative fashion. In the R33 phase, Aim 4 will test the safety of each candidate IS compound in expanded toxicity studies, including a mouse model of cervicovaginal toxicity; and Aim 5 will test the range of antiviral activity against different subtypes of HIV-1 and in a NOD-SCID-hu mouse model of HIV-1 infection. These data will also feed back to the discovery pathway to make new derivatives of IS compounds. Finally, because the ideal microbicide regimen would combine agents that work outside cells to impede virus entry with agents that work inside cells to abort infection for any viruses that do gain entry, Aim 6 will evaluate microbicide combinations that include IS compounds for cooperative activity against HIV-1, in preparation for moving at least one drug candidate into future clinical trials.