Investigating an interface between gp120 and gp41 for HIV entry inhibition

研究 gp120 和 gp41 之间的界面以抑制 HIV 进入

• 批准号: 8264744
• 负责人: MICHAEL B ZWICK
• 金额: $ 18.95万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8264744
• 关键词: AIDS/HIV problem; Address; Affect; Affinity; Antiviral Agents; Binding; Binding Sites; Biological Assay; CCR5 gene; Cells; Chemicals; Complement; Complex; Data; Development; Discrimination; Disulfides; Drug Design; Drug resistance; Elements; Future; Genetic Polymorphism; HIV; HIV Entry Inhibitors; HIV Envelope Protein gp120; HIV Envelope Protein gp41; HIV Fusion Inhibitors; HIV-1; Health; Indium; Investigation; Kinetics; Label; Lead; Libraries; Link; Lipids; Mediating; Modeling; Molecular; Molecular Conformation; Molecular Weight; Mutation; Outcome; Peptides; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Resistance; Role; Site; Son of Sevenless Proteins; Specificity; Structure; Structure-Activity Relationship; Testing; Tracer; Ursidae Family; Variant; Virus; analog; arm; base; combat; design; dimer; drug development; env Glycoproteins; functional outcomes; high throughput screening; inhibitor/antagonist; mimetics; mutant; novel; pandemic disease; research study; resistance mutation; stoichiometry; tool; translational study

DESCRIPTION (provided by applicant): We recently described an HIV fusion inhibitor, PF-68742, that targets a novel site involving the fusion peptide (FP) and disulfide loop (DSL) region of gp41. We have since discovered mutations in the C5 region of gp120 that profoundly affect sensitivity of HIV to PF-68742. The results suggest that PF-68742 binds to native HIV Env in an interface between gp120 and gp41 involving FP, DSL and C5. Interestingly, antiviral activities of several other entry inhibitors to HIV show complex but poorly explained sensitivity to mutations involving the gp120-gp41 interface and/or FP. As examples, VIRIP is a recently described fusion inhibitor that targets FP but HIV resistance and escape to VIRIP has not been well studied, whereas mutations in FP have recently been shown to profoundly affect HIV sensitivity to CCR5-dependent entry inhibitors such as maraviroc (MVC). Interestingly, FP-mediated resistance or escape to these inhibitors has been associated with 'negative' inhibition, in which infectivity of particular variants of HIV is increased in the presence of low concentrations of inhibitor, followed by inhibition at higher concentrations. These commonalities in the functional outcome of different entry inhibitor activities involving mutations at the gp120-gp41 interface have implications for drug development and therefore warrant further investigation. To gain a better understanding of the fine specificity and mechanism of action of PF-68742, in Specific Aim 1, we will use mutagenic profiling to probe structural determinants of Env that affect HIV sensitivity to PF-68742 in comparison to VIRIP and MVC. The experiments will address the role of FP and its mutation in generating multi-class drug resistance, will help outline the functional relationship between FP and other regions of Env, and will inform downstream screens for new entry inhibitors. Potential for synergy of PF-68742 and VIRIP with other entry inhibitors will also be evaluated. In Specific Aim 2, we will prepare tracer labeled versions of PF-68742 and VIRIP to physically probe the exposure of specific elements of their binding sites in different activation states of native Env, as well as for use in probing relevant Env mimetic molecules that bear a gp120-gp41 interface. In Specific Aim 3, we will screen a diverse chemical compound library with the aim of identifying agents that inhibit HIV by binding to and perturbing the conserved subunit interfaces within Env that affect FP. Potential for 'hit' compounds to affect Env stability and complement or synergize with PF-68742, VIRIP or other existing fusion inhibitors will also be tested. Overall, the structure-function information on Env that will be gained, the tools and novel Env trimer- binding assays that we will develop, as well as the new entry inhibitor leads we will identify are relevant to the design and discovery of HIV entry inhibitors to a conserved gp120-gp41 interface in native HIV-1 Env. PUBLIC HEALTH RELEVANCE: New and better drugs are desired that can block HIV before it enters into host cells. To accelerate discovery and development of such drugs, we wish to understand the mechanisms of a recently described, first-in-class HIV entry inhibitor, and distinguish its unique features from those it shares with other key entry inhibitor drugs. We will produce valuable tools for probing its binding site, and then look for relevant new HIV drug leads.

描述（由申请人提供）：我们最近描述了一种 HIV 融合抑制剂 PF-68742，其靶向涉及 gp41 融合肽 (FP) 和二硫键环 (DSL) 区域的新位点。此后，我们发现 gp120 C5 区域的突变深刻影响 HIV 对 PF-68742 的敏感性。结果表明，PF-68742 在 gp120 和 gp41 之间涉及 FP、DSL 和 C5 的界面中与天然 HIV Env 结合。有趣的是，其他几种 HIV 进入抑制剂的抗病毒活性对涉及 gp120-gp41 界面和/或 FP 的突变表现出复杂但难以解释的敏感性。例如，VIRIP 是最近描述的一种针对 FP 的融合抑制剂，但 HIV 对 VIRIP 的耐药性和逃逸尚未得到充分研究，而 FP 的突变最近已被证明会深刻影响 HIV 对 CCR5 依赖性进入抑制剂（如马拉维罗 (MVC)）的敏感性。 ）。有趣的是，FP介导的对这些抑制剂的抵抗或逃逸与“负”抑制有关，其中HIV特定变体的感染性在低浓度抑制剂存在下增加，随后在较高浓度下抑制。涉及 gp120-gp41 界面突变的不同进入抑制剂活性的功能结果的这些共性对药物开发具有影响，因此值得进一步研究。为了更好地了解 PF-68742 的精细特异性和作用机制，在具体目标 1 中，我们将使用诱变分析来探测与 VIRIP 和 MVC 相比影响 HIV 对 PF-68742 敏感性的 Env 结构决定因素。这些实验将解决 FP 及其突变在产生多类耐药性中的作用，将有助于概述 FP 与 Env 其他区域之间的功能关系，并为下游筛选新的进入抑制剂提供信息。还将评估 PF-68742 和 VIRIP 与其他进入抑制剂的协同潜力。在具体目标 2 中，我们将准备 PF-68742 和 VIRIP 的示踪剂标记版本，以物理探测其结合位点的特定元素在天然 Env 的不同激活状态下的暴露情况，以及用于探测具有相关 Env 模拟分子gp120-gp41 接口。在具体目标 3 中，我们将筛选多样化的化合物库，目的是识别通过结合并扰乱 Env 内影响 FP 的保守亚基界面来抑制 HIV 的药物。还将测试“命中”化合物影响 Env 稳定性以及与 PF-68742、VIRIP 或其他现有融合抑制剂互补或协同的潜力。总体而言，将获得的 Env 的结构功能信息、我们将开发的工具和新颖的 Env 三聚体结合测定以及我们将确定的新进入抑制剂先导化合物与 HIV 进入抑制剂的设计和发现相关到天然 HIV-1 Env 中保守的 gp120-gp41 界面。 公众健康相关性：需要新的、更好的药物来阻止艾滋病毒进入宿主细胞。为了加速此类药物的发现和开发，我们希望了解最近描述的一流的 HIV 进入抑制剂的机制，并将其与其他关键进入抑制剂药物共有的独特特征区分开来。我们将生产有价值的工具来探测其结合位点，然后寻找相关的新的艾滋病药物先导化合物。