Conformational Landscape of the HIV-1 Envelope Glycoproteins

HIV-1 包膜糖蛋白的构象景观

• 批准号: 10594418
• 负责人: JOSEPH G SODROSKI
• 金额: $ 63.77万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-15 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10594418
• 关键词: Adopted; Amino Acids; Antibodies; Antibody Response; Binding; Biological; CCR5 gene; CD4 Positive T Lymphocytes; CXCR4 gene; Cell membrane; Cell surface; Cells; Compensation; Complement; Cytoplasmic Tail; Detergents; Disease; Elements; Environment; Exhibits; Exposure to; Funding; Genetic Polymorphism; Glycoproteins; Goals; Grant; HIV; HIV Envelope Protein gp120; HIV envelope protein; Immune Evasion; Immune system; Maintenance; Mass Spectrum Analysis; Mediating; Membrane; Membrane Fusion; Molecular Conformation; Molecular Machines; Nature; Phenotype; Predisposition; Process; Property; Regulation; Research; Resistance; Rest; Sampling; Shapes; Structure; Surface; Testing; Thermodynamics; Tropism; Vaccination; Vaccines; Viral; Virion; Virus; Virus Diseases; Work; conformational conversion; crosslink; design; flexibility; glycoprotein structure; glycosylation; immunogenicity; inhibitor; interest; mutant; neutralizing antibody; novel; prototype; receptor; restraint; small molecule; small molecule inhibitor; therapy design; virus envelope

PROJECT SUMMARY/ABSTRACT The entry of human immunodeficiency virus (HIV-1) into host cells is mediated by the envelope glycoprotein (Env) trimer. The Env trimer consists of three gp120 exterior glycoproteins non-covalently associated with three gp41 glycoproteins, which are anchored in the viral membrane and which possess long (~145-residue) cytoplasmic tails. As the only virus-specific molecule on the viral surface, Env is the major target for host neutralizing antibodies. Env conformational flexibility is essential for virus entry and also contributes to the ability of HIV-1 to evade the host antibody response. During virus entry, the binding of gp120 to the receptors, CD4 and CCR5/CXCR4, triggers conformational changes in the metastable Env that ultimately result in gp41- mediated fusion of the viral and target cell membranes. The HIV-1 Env on virions potentially samples at least three conformations: a “closed” pretriggered conformation (State 1), an “open” CD4-bound conformation (State 3), and an intermediate “partially open” conformation (State 2). Prior to receptor engagement, the State-1 Env conformation is energetically favored, rendering primary HIV-1 strains relatively resistant to the binding of potentially neutralizing antibodies. CD4 binding drives Env from State 1 to State 2 and then into State 3, the prehairpin intermediate. Binding of the State-3 Env to the CCR5 or CXCR4 coreceptor promotes the formation of the highly stable gp41 six-helix bundle, resulting in the fusion of the viral and target cell membranes. Multiple observations indicate that the State-1 Env conformation is metastable and easily disrupted by alteration of Env sequences or extraction of Env from a membrane environment. Indeed, stabilized soluble gp140 trimers or detergent-solubilized Env trimers for which detailed structures are available have been shown to adopt a State-2-like conformation! The proposed work will address our currently incomplete understanding of the State-1 Env conformation. How does HIV-1, despite its tremendous variability, maintain a State-1 Env conformation? We have previously shown that changes in multiple Env amino acid residues can disrupt the State-1 conformation. In the proposed studies, we will identify naturally polymorphic Env residues that, when changed, stabilize the functional State-1 conformation. We will evaluate how State-1-stabilizing and State-1- destabilizing changes in Env interact to determine viral phenotypes. One focus of these studies will be the relationship between the conformation of the gp41 membrane-proximal external region (MPER) and the conformation of the rest of the Env ectodomain. The metastability of the State-1 Env conformation impedes its presentation to the host immune system during natural HIV-1 infection and following vaccination. The proposed studies will inform efforts to produce purified HIV-1 Env trimers stabilized in a State-1 conformation, which serves as the major target of broadly neutralizing antibodies and potent small-molecule entry inhibitors. Understanding how the State-1 Env conformation is regulated should expedite the design of Env-directed therapies and vaccines.

项目摘要/摘要 人类免疫缺陷病毒（HIV-1）进入宿主细胞是由包膜糖蛋白介导的 （env）trimer。 ENV三聚体由三个GP120外部糖蛋白与非共价相关的外部糖蛋白组成 三个GP41糖蛋白，它们锚定在病毒膜上，具有长度（〜145个保留） 细胞质尾巴。作为病毒表面上唯一的病毒特异性分子，Env是宿主的主要目标 中和抗体。 env构象的灵活性对于病毒的进入至关重要，也有助于 HIV-1逃避宿主抗体反应的能力。在病毒进入期间，GP120与接收器的结合， CD4和CCR5/CXCR4，触发了亚稳态ENV中的构象变化，最终导致gp41- 病毒和靶细胞膜的介导的融合。病毒体上的HIV-1环境至少可能样品 三个构象：“封闭”预处理构象（状态1），“开放” CD4结合构象（状态 3），以及中间的“部分开放”构象（状态2）。在受体参与之前，State-1 Env 构象有效地有利于构象，从而使原代HIV-1菌株相对抗性 可能中和抗体。 CD4绑定将环境从状态1到状态2驱动到状态3， 前中级。 State-3 Env与CCR5或CXCR4共肽的结合促进了形成 高度稳定的GP41六螺旋束，导致病毒和靶细胞膜的融合。 多次观察表明，状态-1环境组成是可稳定的，很容易被破坏 ENV序列的改变或从膜环境中提取Env。确实，稳定可溶性 GP140三聚体或确定溶解的Env三聚体已显示为可用的详细结构 采用类似状态2的构象！拟议的工作将解决我们目前不完整的理解 state-1 env构象。 HIV-1如何确定其巨大可变性，保持状态-1 env 构象？我们以前已经表明，多个Env氨基酸残基的变化会破坏 状态1构象。在拟议的研究中，我们将确定自然的多态性env残差，当 变化，稳定功能状态-1构象。我们将评估状态1稳定和状态1-- Inv相互作用的不稳定变化以确定病毒表型。这些研究的重点是 GP41膜膜外部区域（MPER）的构象与 Env Ectodomain其余部分的构象。 状态-1 env构象的亚稳定性阻碍了其向宿主免疫系统的呈现 天然HIV-1感染和疫苗接种后。拟议的研究将为生产纯化的努力提供信息 HIV-1 ENV三聚体以状态1构象稳定，这是广泛中和的主要目标 抗体和潜在的小分子进入抑制剂。了解状态-1 env构象的构象 受监管应加快环境指导疗法和疫苗的设计。