DEVELOPMENT OF RETROCYCLIN MICROBICIDES

预防艾滋病毒-1通过粘膜，特别是经阴道或直肠传播的自行使用的预防性药物的好处是，使易受感染的伙伴能够采取有效措施保护自己。在我们寻找将成为杀微生物剂开发理想模板的分子的过程中，我们利用固相肽合成技术，从其残留物--theta-Defensin假基因--中重建了一种进化上丢失的人类抗菌肽“逆周期蛋白”。逆转录周期蛋白对X4和R5 HIV-1感染的CD4+细胞均有显著的预防作用。更多的研究表明，逆转录周期素抑制HIV-1结合和进入的初始步骤，作为其作用模式。研究发现，下一代逆转录周期素类似物对大多数组和亚型HIV-1的许多初级分离株具有活性。重要的是，我们已经确定了一种先导化合物RC-101，它对HIV-1具有高度的活性，无细胞毒性，适合作为局部杀微生物剂用于临床前开发。基于我们的研究，我们形成了几个关于逆周期蛋白的假设：A)逆周期蛋白可能会抑制阴道粘膜中的HIV-1感染，B)逆周期蛋白和另一种有效的抗HIV-1凝集素(项目1)的糖基化靶点是不同的，因此它们的活性可能是 C)逆转录病毒是有效的抗逆转录病毒药物，适合作为局部阴道杀菌剂进一步开发，以防止艾滋病毒传播。为了验证这些假设，我们建议：1)构建和表征下一代抗HIV-1逆转录周期素类似物，2)评估抗HIV-1活性、稳定性和细胞毒性的候选逆转录周期素制剂，以及3)评价候选逆转录周期素制剂在人体阴道液和血清中的生物有效性。虽然断言逆转周期蛋白的进化缺失导致人类对HIV-1感染的易感性可能是推测的，但逆转周期蛋白是设计能够预防艾滋病毒感染的自然产生的杀菌剂的有希望的线索。

Self-applied prophylactic agents to prevent mucosal, particularly vaginal or rectal, transmission of HIV-1 have the advantage of empowering vulnerable receptive partners to take effective measures for their own protection. In our search for molecules that would be ideal templates for microbicide development, we utilized solid-phase peptide synthesis to recreate an evolutionary lost human antimicrobial peptide "retrocyclin" from its remains, a theta-defensin pseudogene. The ability of retrocyclin to potently prevent infection of CD4+ cells by both X4 and R5 HIV-1 was remarkable. Additional studies revealed that retrocyclin inhibits the initial steps in HIV-1 binding and entry as its mode of action. Next-generation analogs of retrocyclin were found to be active against numerous primary isolates from most groups and subtypes of HIV-1. Importantly, we have identified a lead compound, RC-101, that is highly active against HIV-1, non-cytotoxic, and suitable for preclinical development as a topical microbicide. Based on our studies, we have formed several hypotheses about retrocyclins: A) retrocyclins will likely function to inhibit HIV-1 infection in the vaginal mucosa, B) the glycosylated targets of retrocyclins and cyanovirin N, another potent anti-HIV-1 lectin (Project 1), are different and thus their activities may be complementary, and C) retrocyclins are potent antiretroviral agents suitable for further development as topical vaginal microbicides to prevent HIV transmission. To test these hypotheses, we propose to: 1) Construct and characterize next-generation analogs of anti-HIV retrocyclins, 2) Evaluate candidate retrocyclin formulations for anti-HIV-1 activity, stability and cytotoxicity, and 3) Evaluate candidate retrocyclin formulations for biologic efficacy in human vaginal fluid and serum. While it may be speculative to assert that the evolutionary loss of retrocyclin contributed to the susceptibility of humans to HIV-1 infection, retrocyclins are promising leads for designing naturally occuring microbicides that can prevent HIV infections.