Multifunctional Human Anti-HIV Antibodies

描述（由申请人提供）：在本申请中，我们提出通过将HIV-1融合抑制剂与异常广泛中和抗体（bNABS）结合来创建一类新型抗HIV-1免疫治疗剂。HIV-1所利用的细胞表面受体（CD 4、CCR 5、CXCR 4）是有吸引力的治疗靶点，因为它们没有产生耐药性的压力。不幸的是，HIV包膜蛋白（Env）突变很容易进化以逃避小分子受体阻断。同样，已经发现bNAB可以中和高达90%的测试病毒株，但是当HIV被抗体攻击时，体内抗性迅速发展。在这两种情况下，耐药性都是由于Env的突变，尽管逃避一种分子的突变可以使HIV对另一种分子更敏感。我们的假设是，用抗HIV融合抑制剂修饰的bNAB将是一种非常有效的化合物，并且充分修饰的bNAB将是多功能的，并作为单分子“鸡尾酒”。“这样的化合物将使艾滋病毒的耐药性进化非常困难，因为它需要许多突变才能逃脱bNAB的结合位点和空间阻断的细胞受体位点。我们建议合成经验证的小分子HIV抑制剂，其靶向共受体CCR 5和CXCR 4，以及结合和破坏CD 4/gp 120融合的小分子。这些化合物将被合成为与蛋白质反应性部分连接，这将允许bNAB的特异性修饰。我们的实验室最近开发了两种不同的方法，用于特异性靶向酪氨酸残基。充分表征和非常广泛中和的抗体PG 9和VRCO 1将用作修饰的支架。除了化学修饰之外，我们还将研究产生遗传融合以将PG 9和VRCO 1的Fv联合收割机结合到单个分子上，以及工程化Fc结构域以增加体内半衰期。将评估多特异性抗体中和一组广泛的HIV-1分离株的能力，包括对bNAB和小分子融合抑制剂耐药的菌株。然后将测定成功的候选抗体的半衰期和毒性。最后，多特异性抗体将用于HIV逃逸试验，以验证我们的假设，即这些分子可以构成HIV无法回答的进化挑战。我们预计这项研究的产品将是非常有效和广泛活性的HIV-1免疫治疗剂和药物。 公共卫生相关性：该提案旨在开发特别有效和广泛活性的抗HIV-1治疗药物和药物。虽然目前的逆转录病毒药物鸡尾酒在控制大多数人的HIV-1方面非常有效，但HIV-1最终会对所有药物产生耐药性。我们建议创造一种新型的化学修饰的抗HIV抗体，通过多种机制阻断HIV-1的进入。这种多特异性免疫系统将提供有效的长期抗HIV治疗/预防，并且很难使HIV-1产生耐药性。

DESCRIPTION (provided by applicant): In this application, we are proposing to create a novel class of anti-HIV-1 immunotherapeutics by conjugating HIV-1 fusion inhibitors to exceptionally broadly neutralizing antibodies (bNABS). The cell surface receptors utilized by HIV-1 (CD4, CCR5, CXCR4) are attractive targets for therapy because they are under no pressure to evolve resistance. Unfortunately, HIV envelope protein (Env) mutations are readily evolved to escape small molecule receptor blockade. Likewise, bNABs have been discovered that neutralize up to 90% of tested viral strains but when HIV is challenged with antibodies, in vivo resistance quickly develops. In both cases, the resistance is due to mutations in the Env, although mutations to escape one molecule can make HIV more sensitive to another. Our hypothesis is that a bNAB modified with anti-HIV fusion inhibitor would be an exceptionally potent compound and that a sufficiently modified bNAB would be multifunctional and act as single molecule "cocktail." Such a compound would make evolution of resistance very difficult for HIV because it would require many mutations to escape the binding sites of the bNABs and the sterically blocked cell receptor sites. We propose to synthesize validated small molecule HIV inhibitors that target the co-receptors CCR5 and CXCR4, as well as, small molecules that bind and disrupt the CD4/gp120 fusion. These compounds will be synthesized linked to protein reactive moieties which will allow for specific modification of bNABs. Our lab has recently developed two different approaches for specific targeting of tyrosine residues for this purpose. The well characterized and very broadly neutralizing antibodies PG9 and VRCO1 will serve as the scaffold for modification. In addition to chemical modification, we will also investigate creating genetic fusions to combine the Fv's of PG9 and VRCO1 onto a single molecule, as well as, engineering the Fc domain to increase in vivo half-life. Multi-specific antibodies will be assessed for their ability to neutralize a broad panel of HIV-1 isolates including strains which are resistant to the bNABs and the small molecule fusion inhibitors. Successful candidate antibodies will then be assayed for half-life and toxicity. Finally, multi-specific antibodies will be used in an HIV escape assay to test our hypothesis that these molecules can pose an evolutionary challenge that HIV cannot answer. We anticipate that the products of this research will be exceptionally potent and broadly active HIV-1 immunotherapeutics and prophylactics. PUBLIC HEALTH RELEVANCE: This proposal aims to develop exceptionally potent and broadly active anti-HIV-1 therapeutics and prophylactics. Although current retroviral drug cocktails are very effective in controlling HIV-1 in most individuals, HIV-1 eventually evolves resistance to all drugs. We propose to create a novel type of chemically modified anti-HIV antibody that blocks HIV-1 entry through multiple mechanisms. This multi-specific immunotherapeutic would provide potent long-lived anti-HIV therapy/prophylaxis and would be very hard for HIV-1 to evolve resistance against.