Drug development for Vif-APOBEC3G in HIV-1/AIDS

我们和其他人最近的研究已经基本上阐明了HIV-1编码的病毒的作用， 感染因子（Vif），中和淋巴细胞和巨噬细胞中存在的有效抗病毒系统 和一些白血病T细胞系这种抗病毒系统主要涉及胞苷脱氨酶 APOBEC 3G（A3 G）和/或ASF，它们被整合到HIV-1核心中，在那里它们致命地超突变 新合成的病毒逆转录物。Vif与A3 G和ASF结合并诱导其多聚泛素化 和降解，从而将它们从受感染的细胞中清除，并阻止它们掺入HIV-1 后代尽管研究人员使用一种Vif作为标准，但HIV-1 Vif具有高度的差异性， 已经发现，天然HIV-1分离株编码Vifs，其混杂地结合所有APOBEC 3旁系同源物， 对它们的浓度有着广泛而独特的影响。此外，APOBECSs共表达于 在HIV-1易感细胞中，它们的数量和比例不同，并且它们广泛地异源寡聚化， 协作和诱导抗病毒网络。我们的研究结果表明，Vif多样性在一定程度上是一种适应性 对APOBEC 3网络在不同细胞和区室中的多样性的反应，它可能发挥作用， 它在HIV-1发病机制中起着关键作用，在抗Vif药物开发中也应该加以考虑。基于 根据这些结果和大量的初步证据，我们提出三个实质性的协同目标： (1)开发一系列强大的筛选平台，用于识别抑制多种 哺乳动物细胞内的病毒感染因子。(2)我们发现HIV-1 Vif是在酵母中作为可溶性蛋白质产生的， 与A3 G合作。产生大量的Vif及其A3 G结合亚结构域和A3 G， 酵母毕赤酵母作为分析抑制剂机制的资源，并支持高通量 目标3的筛选系统。(3)优化ELISA测定以筛选和分析抑制Vif的化合物- A3 G结合并测量不同Vif对A3 G和其他胞苷脱氨酶的亲和力。这个程序 建立在最近的见解，开发和优化新的抑制剂筛选方法和研究 作为高通量筛选有效抗Vif治疗剂的必要前奏。

Recent studies by ourselves and others have substantially elucidated the role of the HIV-1 encoded viral infectivity factor (Vif) in neutralizing a potent antiviral system that occurs in lymphocytes and macrophages and some leukemic T cell lines. This antiviral system principally involves the cytidine deaminases APOBEC3G (A3G) and/or ASF, which are incorporated into HIV-1 cores where they lethally hypermutate newly synthesized viral reverse transcripts. Vif binds to A3G and ASF and.induces their polyubiquitination and degradation, thereby eliminating them from infected cells and precluding their incorporation into HIV-1 progeny. Although researchers have used one Vif as a standard, HIV-1 Vifs are highly divergent and we have found that natural HIV-1 isolates encode Vifs that bind promiscuously to all APOBEC3 paralogs but have widely distinctive effects on their concentrations. In addition, the APOBECSs are coexpressed in different amounts and proportions in HIV-1 susceptible cells, and they broadly heterooligomerize to form a collaborative and inducible antiviral network. Our results suggest that Vif diversity is partly an adaptive response to the diversity of the APOBEC3 network in different cells and compartments, that it may play a critical role in HIV-1 pathogenesis, and that it should also be considered in anti-Vif drug development. Based on these results and on substantial preliminary evidence, we propose three substantial and synergistic aims: (1) Develop a robust series of screening platforms for identification of small molecules that inhibit diverse Vifs within mammalian cells. (2) We found that HIV-1 Vif is made in yeast as a soluble protein that associates with A3G. Produce substantial amounts of Vif, and its A3G-binding subdomain and A3G in the yeast Pichia pastorisas a resource to analyze inhibitor mechanisms, and to support the high throughput screening system of aim 3. (3) Optimize ELISA assays to screen and analyze compounds that inhibit Vif- A3G binding and to measure affinities of diverse Vifs for A3G and other cytidine deaminases. This program builds on recent insights to develop and to optimize novel inhibitor screening approaches and investigational resources for AIDS, as an essential prelude to high throughput screening for effective anti-Vif therapeutics.