Targeting HIV-1 Envelope glycoprotein incorporation

描述（由申请人提供）：我们最近的工作确定了一个新的目标，为发展抗艾滋病毒疗法。我们证明了细胞内宿主猴蛋白阻止HIV-1包膜（Env）糖蛋白掺入新生病毒体。我们获得了几条证据，表明猴蛋白通过干扰HIV-1 Gag-Env相互作用（特异性Env掺入出芽病毒体的先决条件）来阻止Env掺入。最重要的是，这些缺乏Env的病毒粒子是非传染性的。因此，Env掺入代表了开发新的抗HIV-1药物的新靶点。这一观察结果让人想起CD 4介导的Env掺入病毒体的抑制，这也是Retrovirox药物发现工作的主题。重要的是，我们获得的证据表明，Env掺入缺陷是由于Env无法到达细胞表面。目前还没有针对艾滋病毒生命周期这一关键步骤的药物。此外，据我们所知，还没有尝试鉴定阻断Env细胞表面表达和Env掺入病毒体的小化合物。我们最近筛选了少量化合物（1，500）作为Env掺入的抑制剂。这个试验性实验使我们能够鉴定出一些命中化合物，这些化合物阻止Env掺入，而对人类细胞没有明显的毒性。这些发现证明了小分子可以阻断Env掺入并使病毒粒子无感染性的概念验证，并使本文提出的项目可行。本I期研究的目的是使用特异性和灵敏性HIV-1 Env掺入试验完成更大文库（20，000种化合物）的筛选。在这一阶段I申请的成功被定义为至少10个药物样化合物的里程碑识别与IC 50低于5 5 M在HIV复制试验和最小的细胞毒性（治疗指数大于10）。具有这些特征的先导化合物将在II期项目中针对效价、特异性和生物利用度进行优化。第二项提案旨在推进这些化合物的临床前开发，以支持人体试验。该提案的具体目标是：1）开发HIV-1包膜掺入试验，以及; 2）筛选小分子文库。公共卫生相关性：截至2007年底，全世界有3 300万人感染艾滋病毒。尽管在抗逆转录病毒疗法方面取得了进展，但副作用和出现对现有药物具有抗药性的病毒给艾滋病毒的治疗带来了重大问题。我们建议通过一种新的机制来鉴定和表征阻断HIV的抗逆转录病毒化合物。这些独特的化合物可用于治疗HIV感染。

DESCRIPTION (provided by applicant): Our most recent work identified a novel target for the development of anti-HIV therapies. We demonstrated that intracellular host monkey proteins prevent the incorporation of HIV-1 envelope (Env) glycoproteins into nascent virions. We obtained several lines of evidence that suggest that the monkey proteins preclude Env incorporation by interfering with HIV-1 Gag-Env interaction, a precondition for specific Env incorporation into budding virions. Most importantly, these virions, which lack Env, are noninfectious. Thus, Env incorporation represents a novel target for the development of new anti-HIV-1 agents. This observation is reminiscent of the CD4-mediated inhibition of Env incorporation into virions, which is also the subject of drug discovery efforts at Retrovirox. Importantly, we obtained evidence that the Env incorporation defect arises from the inability of Env to reach the cell surface. No drug targeting this critical step of the HIV life cycle is currently available. Moreover, to our knowledge, there has been no attempt to identify small compounds blocking Env cell surface expression and Env incorporation into virions. We recently screened a small number of compounds (1,500) for inhibitors of Env incorporation. This pilot experiment allowed us to identify a few hit compounds, which prevent Env incorporation without apparent toxicity to human cells. These findings demonstrate proof-of-concept that small molecules can block Env incorporation and render virions noninfectious, and make the project proposed here feasible. The objective of this phase I study is complete the screening of a larger library (20,000 compounds) using a specific and sensitive HIV-1 Env incorporation assay. Success in this Phase I application is defined as the milestone identification of at least 10 drug-like compounds with IC50s below 5 5M in HIV replication assays and minimal cytotoxicity (therapeutic index greater than 10). Lead compounds with these profiles will be optimized for potency, specificity and bioavailability in a Phase II project. This second proposal will aim at advancing the preclinical development of these compounds to support human trials. The specific aims of this proposal are: 1) Development of an HIV-1 Envelope incorporation assay, and; 2) Screening of small-molecule libraries. PUBLIC HEALTH RELEVANCE: As of the end of 2007, 33 million people worldwide are infected with HIV. Despite advances in antiretroviral therapies, side-effects and the emergence of viruses resistant to currently available drugs pose important problems for the treatment of HIV. We propose to identify and characterize antiretroviral compounds that block HIV through a novel mechanism. These unique compounds could be used for the treatment of HIV infection.