HIV and SIV Envelope Glycoproteins

描述（由申请人提供）：对HIV-1和密切相关的SIV与其靶细胞相互作用、结合和融合所涉及的分子的结构和功能方面的详细了解，对于我们理解艾滋病的疾病过程以及合理设计诊断试剂、疫苗和其他治疗剂至关重要。感染过程中最重要的两种分子，即包膜糖蛋白（Env）糖蛋白、SU（表面）和TM（跨膜），在结构水平上仅部分表征，其许多重要特征仍不清楚。这些领域的不确定性包括可变环的方向，结合和融合过程中发生的一些结构变化，以及促进或抑制Ab介导的中和作用的特征。另一个不确定的领域涉及Env蛋白在不同类型和发育阶段的病毒颗粒上的分布。该提案描述了旨在应用新方法确定HIV-1、HIV-2和SIV包膜（Env）表面（SU，gp 120）和跨膜（TM，gp 41）区域的3D形态的研究，因为它们在病毒表面和纯化的重组形式中表达。我们的目标是确定Env刺突的数量，位置，方向和结构细节，单独和与单克隆抗体和配体的复合物，在各种形式的HIV和SIV病毒颗粒的表面上。此外，我们将扩大我们以前的表位和反应位点作图研究的单个分子和复合物进行三维结构分析的2D阵列的重组可溶性三聚体Env蛋白和免疫复合物。主要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模型构建来分析完整的病毒体，包括将先前描述的原子结构拟合到我们的3D模型中。与公共卫生的相关性：这项拨款提案旨在提供有关艾滋病病毒表面蛋白的关键信息，这些蛋白是感染的原因。这些蛋白质也是免疫系统对抗艾滋病的抗体防御的目标。所提供的信息有助于设计治疗剂和疫苗。

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.