Subversion of hepatocyte phosphoinositide metabolism by hepatitis C virus

丙型肝炎病毒破坏肝细胞磷酸肌醇代谢

• 批准号: 9029323
• 负责人: Andrew W. Tai
• 金额: $ 33.82万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-13 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9029323
• 关键词: 1-Phosphatidylinositol 4-Kinase; Accounting; Adverse drug effect; Affect; Antiviral Agents; Area; Binding; Binding Proteins; Biochemical; Cells; Cellular Membrane; Cholesterol; Chronic Hepatitis C; Clinical; Family Picornaviridae; Generations; Goals; Health; Health Benefit; Hepatitis C; Hepatitis C virus; Hepatitis C-Like Viruses; Hepatocyte; Human; Imaging Techniques; Individual; Integration Host Factors; Internet; Lead; Life; Life Cycle Stages; Lipids; Liver Failure; Liver diseases; Membrane; Membrane Proteins; Metabolism; Modeling; Molecular; Names; PIK4CB gene; Peripheral; Phosphatidylinositols; Phosphotransferases; Physiological; Population; Primary carcinoma of the liver cells; Proteins; Public Health; RNA Viruses; RNA interference screen; RNA replication; Recruitment Activity; Regulation; Research; Role; Serine Protease; Structure; Testing; Therapeutic Agents; United States National Institutes of Health; Viral; Viral Proteins; Virus; Virus Replication; base; cofactor; design; innovation; inorganic phosphate; insight; liver transplantation; membrane activity; new therapeutic target; novel; novel strategies; novel therapeutics; oxysterol binding protein; particle; phosphatidylinositol 4-phosphate; therapeutic development; treatment response; viral resistance

DESCRIPTION (provided by applicant): Chronic hepatitis C virus (HCV) infection develops in 70-80% of all exposed individuals and affects 3% of the world's population. While new drugs that directly target the viral NS3-4A serine protease have been approved for clinical use this year, there remains a need for more effective and better-tolerated HCV therapies. Our long- term goals are to define host-HCV molecular interactions and in so doing, to identify novel therapeutic agents for HCV therapy. HCV, like all other positive-sense single-stranded RNA viruses studied to date, induces the formation of specific membranous structures (called membranous webs) within infected cells for its own replication. Multiple RNAi screens have identified a critical role for a host protein phosphatidylinositol 4-kinase (PI 4-kinase) named PI4KA in HCV replication, most likely at the level of membranous web formation. Intriguingly, three other positive-sense single-stranded RNA viruses subvert the related PI 4-kinase PI4KB for their own replication. The objective of this proposal is to understand how the host hepatocyte protein PI4KA and its product PI 4-phosphate (PI(4)P) support HCV replication. Our central hypothesis is that HCV replication requires the local generation of PI(4)P, which in turn is necessary for the recruitment of effector proteins to the nascent membranous web. The specific aims of the project are to (1) Define the functional domains of PI4KA and its regulation; (2) Identify the phosphoinositide-dependent steps in the HCV life cycle; (3) Identify and characterize downstream effectors of PI4KA and PI(4)P in the HCV life cycle. We will use a variety of biochemical, cell-based, and imaging techniques to accomplish the proposed research. The proposed research is innovative as (1) the model of web assembly presented in this proposal is novel; (2) the mechanisms by which PI4KA is regulated in the host cell and in the context of HCV replication have not been studied (Aim 1); (3) The mechanisms by which PI(4)P and other phosphoinositides support HCV replication has not been previously pursued (Aims 2 and 3); (4) The use of inducible and selective depletion of phosphoinositides (Aim 2) has not been previously used to study viral replication. We expect that the proposed research may have direct public health benefits, as a better understanding of the mechanisms by which PI4KA and host phosphoinositides support viral replication may lead to novel approaches to the treatment of chronic HCV infection. A better understanding of the HCV-host relationship is a stated goal of the NIH Action Plan for Liver Disease Research (Goal B2a). Moreover, completion of the proposed aims will also lead to new insights into the physiological functions and regulation of PI4KA, areas that are currently poorly understood.

描述（由申请人提供）： 70-80% 的接触者患有慢性丙型肝炎病毒 (HCV) 感染，影响世界人口的 3%。虽然直接靶向病毒 NS3-4A 丝氨酸蛋白酶的新药今年已被批准用于临床，但仍然需要更有效、耐受性更好的 HCV 疗法。我们的长期目标是确定宿主-HCV 分子相互作用，并在此过程中确定用于 HCV 治疗的新型治疗药物。 HCV 与迄今为止研究的所有其他正链单链 RNA 病毒一样，会诱导受感染细胞内形成特定的膜结构（称为膜网）以进行自身复制。多次 RNAi 筛选已经确定了名为 PI4KA 的宿主蛋白磷脂酰肌醇 4 激酶（PI 4 激酶）在 HCV 复制中的关键作用，很可能是在膜网形成的水平上。有趣的是，另外三种正义单链 RNA 病毒会破坏相关的 PI 4 激酶 PI4KB 进行自身复制。该提案的目的是了解宿主肝细胞蛋白 PI4KA 及其产物 PI 4-磷酸 (PI(4)P) 如何支持 HCV 复制。我们的中心假设是，HCV 复制需要局部生成 PI(4)P，而这又是将效应蛋白招募到新生膜网所必需的。该项目的具体目标是（1）定义PI4KA的功能域及其调控； (2) 确定HCV生命周期中依赖磷酸肌醇的步骤； (3) 识别并表征HCV生命周期中PI4KA和PI(4)P的下游效应子。我们将使用各种生化、细胞和成像技术来完成拟议的研究。该研究具有创新性，因为（1）该提案中提出的网络组装模型是新颖的； (2) 尚未研究 PI4KA 在宿主细胞和 HCV 复制背景下的调节机制（目标 1）； (3) PI(4)P 和其他磷酸肌醇支持 HCV 复制的机制以前尚未被研究过（目标 2 和 3）； (4) 磷酸肌醇的诱导性和选择性消耗（目标 2）以前尚未用于研究病毒复制。我们预计拟议的研究可能具有直接的公共卫生益处，因为更好地了解 PI4KA 和宿主磷酸肌醇支持病毒复制的机制可能会带来治疗慢性 HCV 感染的新方法。更好地了解 HCV-宿主关系是 NIH 肝病研究行动计划（目标 B2a）的既定目标。此外，完成所提出的目标还将带来对 PI4KA 生理功能和调节的新见解，而这些领域目前知之甚少。