Development of RC-101 as an Intravaginal Anti-HIV-1 Topical Microbicide

通过粘膜表面的性传播一直是HIV-1最常见的传播途径 在世界各地。尽管HIV-1疫苗的研发受到了极大的关注， 进展缓慢，迫切需要找到替代办法，如专题 杀微生物剂，以控制艾滋病毒-1的传播。在寻找抗HIV-1活性的新化合物的过程中，我们 发现被称为逆周期素类的环状抗菌肽是HIV-1的有效抑制剂 复制。我们已经合成并测试了近120个逆转周期素类似物的抗HIV-1活性，以及 确定赖氨酸类似物RC-101最适合作为局部杀菌剂开发。RC-101 被证明对R5和X4 HIV-1具有活性，并通过阻止融合复合体的启动而起作用 通过与gp41上的七肽重复区域2结合，排除了六螺旋束的形成。还展出了RC-101 在器官型宫颈阴道上皮中几乎没有细胞毒性或诱导促炎细胞因子和 宫颈器官培养，不凝集红细胞，非常稳定，可以 配制成薄膜，用于阴道内应用。膜制剂RC-101在五条辫子中的初步研究 猕猴发现这种多肽是安全的，没有明显的毒性，并且与 宫颈阴道上皮细胞。基于我们的发现，我们形成了关于RC-101的几个假设： A)RC-101是稳定的和生物可用的，因此可能起到抑制阴道粘膜中艾滋病毒-1感染的作用， B)RC-101(进入/融合抑制物)和CSIC(非核苷类逆转录酶抑制物 由项目1开发)具有不同的行动机制，因此其活动将是相辅相成的 在预防艾滋病毒传播方面，以及c)RC-101，作为一种控释产品，可以提供 防止异性传播艾滋病毒-1的长期保护措施。在多学科的帮助下 团队，我们将通过1)确定在生物体液中的广谱有效性、稳定性来检验这些假说 以及单独和与CSIC联合诱导RC-101对HIV-1耐药性的能力，以及2)评估 有机硅弹性体环，单独和与CSIC组合配制的RC-101有机类型 猴子的宫颈阴道组织和局部阴道给药。这些研究涉及一项 高度协作和迭代的方法，将RC-101与CSIC结合起来开发为一个环 阴道内局部使用杀微生物剂。

Sexual transmission through mucosal surfaces has been the most common route of HIV-1 spread throughout the world. Although much attention has been focused on vaccine development for HIV-1, progress has been slow and there is an urgent need to find alternative approaches, such as topical microbicides, to target the spread of HIV-1. In our search for novel compounds active against HIV-1, we discovered that the cyclic antimicrobial peptides called retrocyclins were potent inhibitors of HIV-1 replication. We have synthesized and tested the anti-HIV-1 activity of nearly 120 analogs of retrocyclin, and determined that the lysine analog RC-101 was best suited for development as a topical microbicide. RC-101 was shown to be active against R5 and X4 HIV-1, and acts by preventing the initiation of the fusion complex by binding the heptad repeat region 2 on gp41, precluding six helix bundle formation. RC-101 also exhibited little to no cytotoxicity or induction of proinflammatory cytokines in organotypic cervicovaginal epithelia and cervical organ culture, did not hemagglutinate red blood cells, was remarkably stable, and could be formulated into thin films for intravaginal application. Pilot studies with film-formulated RC-101 in five pigtail macaques revealed that the peptide was safe, exhibited no appreciable toxicity, and was associated with cervicovaginal epithelial cells. Based on our findings, we have formed several hypotheses about RC-101: a) RC-101 is stable and bioavailable, thus will likely function to inhibit HIV-1 infection in the vaginal mucosa, b) RC-101 (an entry/fusion inhibitor) and CSIC (a non-nucleoside reverse transcriptase inhibitor being developed by Project 1) have different mechanisms of action and thus their activities will be complementary in preventing HIV transmission, and c) RC-101, formulated as a controlled-release product, can provide long-term protection against heterosexual HIV-1 transmission. With assistance from a multidisciplinary team, we will test these hypotheses by 1) determining the broad spectrum efficacy, stability in biologic fluids and ability to induce HIV-1 resistance of RC-101, alone and in combination with CSIC, and 2) evaluating silicone elastomer ring-formulated RC-101, alone and in combination with CSIC, in organotypic cervicovaginal tissues and following topical vaginal administration in monkeys. These studies involve a highly collaborative and iterative approach to develop RC-101 in combination with CSIC as a ring-formulated intravaginal topical microbicide.