Viral Hijacking of Host Membrane Trafficking Pathways

宿主膜运输途径的病毒劫持

• 批准号: 8779706
• 负责人: John C. Guatelli
• 金额: $ 61.2万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8779706
• 关键词: Adaptor Signaling Protein; Antiviral Agents; Binding; Biochemical; Biological; CD4 Antigens; Capsid Proteins; Cell membrane; Cell surface; Cells; Cellular Membrane; Chimeric Proteins; Clathrin Adaptor Protein Complexes; Clathrin Adaptors; Complex; Cytoplasmic Tail; Cytotoxic T-Lymphocytes; Down-Regulation; Drug Targeting; Electron Microscopy; Environment; Event; Goals; HIV; HIV Infections; Health; Host Defense; Immune; Immunity; Immunologic Surveillance; Infection Control; Integral Membrane Protein; Investigation; Lead; Life; Link; Lipid Bilayers; Macaca mulatta; Maps; Mediating; Membrane; Membrane Lipids; Membrane Protein Traffic; Membrane Proteins; Methods; Modeling; Molecular; Mutagenesis; Nature; Outcome; Pathway interactions; Peripheral; Proteins; Research; Research Project Grants; Role; SIV; Solutions; Structure; System; Testing; Transcription Factor AP-1; Transcription Factor AP-2 Alpha; Validation; Viral; Viral Proteins; Virion; Virus; Virus Diseases; Work; X-Ray Crystallography; aqueous; base; cofactor; design; empowered; link protein; nef Protein; nonhuman primate; novel; novel strategies; particle; pathogen; prevent; protein complex; protein degradation; protein transport; research study; restraint; tool; ubiquitin ligase

DESCRIPTION (provided by applicant): The host cell surface has a diverse repertoire of immune molecules to detect and attack foreign particles, including those introduced upon viral infections. Viruses, in turn, have developed an equally impressive arsenal of methods to evade host defenses, such as hijacking cellular membrane trafficking machinery to downregulate host innate and adaptive immune molecules. For example, HIV removes its primary receptor, CD4, from cellular membranes to avoid interference with viral release and infectivity; it prevents MHC-I from reaching the cell surface to evade immune surveillance by cytotoxic T cells; and it removes the innate host restriction factor BST2 (also known as tetherin) from the cell surface to allow for the efficient release of progeny virions. HIV Vpu, a transmembrane protein, and HIV Nef, a peripheral membrane protein, accomplish these tasks by linking targeted proteins to components of the host protein trafficking machinery, thereby inactivating host defense proteins through mislocalization and degradation. The focus of this proposal is to establish the mechanisms by which Nef and Vpu hijack host membrane trafficking pathways to down regulate the expression of immune molecules at the cell surface. Our approach includes structure determination by X-ray crystallography and single particle electron microscopy. It features novel fusion-protein strategies that allow the investigation of membrane-mediated interactions in aqueous solution. It features cell biologic and virologic validation of the complexes at both the molecular and structural levels. Our work will significantly advance our understanding of a diverse range of host-viral interactions at cellular membranes and identify new antiviral drug-targets. Inhibition of these targets would disable viral modulation of cellular membranes and potentially empower host immunity to more effectively control an HIV infection. Moreover, the experimental systems devised for our research project will provide valuable new tools for the studies of host-pathogen relationships and membrane protein interactions.

描述（由申请人提供）：宿主细胞表面具有多种免疫分子来检测和攻击外来颗粒，包括病毒感染时引入的颗粒。反过来，病毒也开发出了一系列同样令人印象深刻的方法来逃避宿主防御，例如劫持细胞膜运输机制来下调宿主先天性和适应性免疫分子。例如，HIV从细胞膜上去除其主要受体CD4，以避免干扰病毒释放和感染性；它阻止 MHC-I 到达细胞表面以逃避细胞毒性 T 细胞的免疫监视；它从细胞表面去除先天宿主限制因子 BST2（也称为系链蛋白），以允许子代病毒粒子的有效释放。 HIV Vpu（一种跨膜蛋白）和 HIV Nef（一种外周膜蛋白）通过将目标蛋白连接到宿主蛋白运输机制的组件来完成这些任务，从而通过错误定位和降解使宿主防御蛋白失活。 该提案的重点是建立 Nef 和 Vpu 劫持宿主膜运输途径以下调细胞表面免疫分子表达的机制。我们的方法包括通过 X 射线晶体学和单粒子电子显微镜进行结构测定。它具有新颖的融合蛋白策略，可以研究水溶液中膜介导的相互作用。它的特点是在分子和结构水平上对复合物进行细胞生物学和病毒学验证。我们的工作将显着增进我们对细胞膜上多种宿主-病毒相互作用的理解，并确定新的抗病毒药物靶点。抑制这些目标将使病毒对细胞膜的调节失效，并可能增强宿主免疫力，从而更有效地控制艾滋病毒感染。此外，为我们的研究项目设计的实验系统将为研究宿主-病原体关系和膜蛋白相互作用提供有价值的新工具。