HIV and SIV Envelope Glycoproteins

描述(由申请人提供)：详细了解参与HIV-1和密切相关的SIV与其靶细胞的相互作用、结合和融合的分子的结构和功能方面的知识，对于我们理解艾滋病的疾病过程以及合理设计诊断试剂、疫苗和其他治疗剂是基本的。在感染过程中最重要的两个分子，即包膜糖蛋白(Env)糖蛋白，SU(表面)和TM(跨膜)，只是在结构水平上的部分特征，它们的许多重要特征仍然不清楚。这些不确定的领域包括可变环的方向，结合和融合过程中发生的一些结构变化，以及促进或抑制抗体介导的中和的特征。另一个不确定的领域涉及包膜蛋白在不同类型和发育阶段的病毒颗粒上的分布。这项建议描述了旨在应用新的方法来确定HIV-1、HIV-2和SIV包膜(Env)表面(SU，gp120)和跨膜(TM，gp41)区域的3D形态的研究，因为它们在病毒表面表达和以纯化的重组形式表达。我们的目标是确定不同形式的HIV和SIV病毒颗粒表面上单独或与单抗和配体复合的Env尖峰的数量、位置、方向和结构细节。此外，我们还将通过对重组可溶性三聚体环境蛋白和免疫复合体的2D阵列进行3D结构分析，来扩展我们之前对单个分子和复合体的表位和反应位点的研究。主要的方法将是通过最先进的冷冻电子显微镜(CryoEM)断层扫描和计算机辅助建模来分析完整的病毒粒子，包括将以前描述的原子结构拟合到我们的3D模型中。与公共卫生相关：赠款提案旨在提供有关导致感染的艾滋病病毒表面蛋白的关键信息。这些蛋白质也是免疫系统针对艾滋病的抗体防御的目标。提供的信息可能有助于治疗剂和疫苗的设计。

DESCRIPTION (provided by applicant): Detailed knowledge of the structural and functional aspects of the molecules involved in the interaction, binding, and fusion of HIV-1 and the closely related SIV with their target cells is fundamental to our understanding of the disease processes in AIDS and to the rational design of diagnostic reagents, vaccines and other therapeutic agents. Two of the most important molecules in the infectious process, namely the envelope glycoproteins (Env) glycoproteins, SU (surface), and TM (transmembrane), are only partially characterized at the structural level with many of their important features still poorly defined. These areas of uncertainty include the orientation of the variable loops, some of the structural changes that occur during the binding and fusion processes, and the features which foster or inhibit Ab-mediated neutralization. Another area of uncertainty involves the distribution Env proteins on viral particles of various types and developmental stages. This proposal describes investigations aimed at applying new approaches for the determination of the 3D morphology of the HIV-1, HIV-2, and SIV envelope (Env) surface (SU, gp120) and transmembrane (TM, gp41) regions as they are expressed on the viral surface and in purified recombinant form. Our goals are to determine the numbers, locations, orientations, and structural details of Env spikes, both alone and in complex with monoclonal antibodies and ligands, on the surface of various forms of HIV and SIV viral particles. In addition we will expand upon our previous epitope and reactive-site mapping studies of individual molecules and complexes by conducting 3D structural analyses on 2D arrays of recombinant soluble trimeric Env proteins and immune complexes. The primary methodologies will be the analysis of intact virions by state-of-the-art cryo-electron microscopic (cryoEM) tomography and computationally assisted model building, including fitting of previoulsy described atomic structures into our 3D models. Relevance to Public Health: The grant proposal is designed to provide key information on the AIDS viral surface proteins that are responsible for infection. These proteins also are the targets of the immune system's antibody defenses against AIDS. The information provided could help in the design of therapeutic agents and vaccines.