Antivirals for Hepatitis C Targeting Phosphoinositide Metabolism

描述（由申请人提供）：Gelman博士是有机化学和传染病方面的医学博士/博士，他的近期职业目标是分子病毒学和相关学科的高级培训，他的长期职业目标是在学术医学领域获得职位，他建议使用一类新的小分子——PI4K抑制剂来研究丙型肝炎病毒。拟议的工作将在斯坦福大学Jeffrey Glenn博士的实验室进行，共同导师Kevan Shokat博士（UCSF细胞和分子药理学），顾问Gary Peltz博士（麻醉，药代动力学和药物代谢专业知识）和Michael Lin博士（儿科/生物工程，活细胞生物分子成像专业知识）。斯坦福大学有一个充满活力的传染病部门，在博士后准备过渡到教师职位时，为他们提供广泛的职业支持。丙型肝炎病毒（HCV）感染了全球人口的2-3%，即大约1.7亿人。慢性丙型肝炎病毒感染有25%的肝硬化风险和较小但显著的危及生命的肝细胞癌风险。在美国，HCV引起的肝硬化是肝移植的主要指征，但HCV总是在移植器官中复发。目前HCV治疗的标准护理是一个12-48周（取决于基因型和反应）的聚乙二醇干扰素-利巴韦林疗程，这是昂贵的，有多种严重的副作用，只有50-80%的有效性。尽管多种新型抗丙型肝炎病毒疗法正处于不同的发展阶段，但多种药物联合治疗可能是有效控制感染所必需的。HCV非结构蛋白NS5A与膜磷酸肌肽PI(4,5)P2或PIP2特异性相互作用。这种相互作用和产生PIP2的磷酸肌苷激酶（PI4K）活性似乎都是病毒复制所必需的。拟制的研究包括对抑制PI4K的化合物的潜力进行表征(1)作为一类新型的HCV抗病毒药物，其机制与已知的抗病毒药物无关；(2)作为一种化学工具来研究HCV生命周期，特别是HCV复制酶复合物的动力学，使用荧光蛋白标签来可视化活细胞中的复制酶复合物。PI4K是一种宿主酶，与抑制病毒酶相比，抑制PI4K可能与产生耐药性的更高障碍有关。每年导致肝癌、肝功能衰竭和数千人死亡的丙型肝炎病毒（HCV）依赖于它所感染细胞中的一种名为PI4K的酶。我们将研究一类可以阻断PI4K的化合物，以确定它们是否可以导致一类新的抗HCV药物。我们还将使用这些化合物来研究HCV如何自我复制以及这一过程如何依赖于PI4K的活性。

DESCRIPTION (provided by applicant): Dr. Gelman, an MD/PhD with prior training in organic chemistry and infectious diseases, whose immediate career goal is advanced training in molecular virology and related disciplines and whose long-term career goal is a position in academic medicine, proposes to study the hepatitis C virus using a novel class of small molecules, the PI4K inhibitors. The proposed work will take place at Stanford University, in Dr. Jeffrey Glenn's laboratory, with co-mentor Dr. Kevan Shokat (UCSF Cellular and Molecular Pharmacology) and consultants Dr. Gary Peltz (Anesthesia; expertise in pharmacokinetics and drug metabolism) and Dr. Michael Lin (Pediatrics/Bioengineering; expertise in imaging biological molecules in living cells). Stanford has a vibrant Infectious Diseases division and extensive career support for postdoctoral fellows as they prepare to make the transition to faculty positions. The hepatitis C virus (HCV) infects between 2-3% of the global population, or roughly 170 million people. Chronic HCV infection carries a 25% risk of cirrhosis and a smaller but significant risk of life-threatening hepatocellular cancer. Cirrhosis due to HCV is the leading indication for liver transplant in the US, but HCV invariably recurs in the transplanted organ. The current standard of care for HCV treatment is a 12-48 week (depending on genotype and response) course of peginterferon-ribavirin, which is costly, has multiple serious side effects, and is only 50-80% effective. Although multiple new classes of anti-HCV therapies are in various stages of development, multidrug combination therapy is likely to be necessary for effective control of the infection. The HCV nonstructural protein NS5A interacts specifically with membrane phosphoinositide PI(4,5)P2, or PIP2. Both this interaction and the phosphoinositide 4-kinase (PI4K) activity that generates PIP2 appear to be necessary for viral replication. The proposed research involves characterization of the potential of compounds designed to inhibit PI4K as (1) a novel class of antivirals for HCV with a mechanism unrelated to known antiviral drugs and (2) a chemical tool to investigate the HCV life cycle, and particularly the dynamics of the HCV replicase complex, using fluorescent protein tags to visualize replicase complexes in living cells. Inhibition of PI4K, which is a host enzyme, may be associated with higher barriers to development of resistance than is inhibition of viral enzymes. The hepatitis C virus (HCV), which causes liver cancer, liver failure, and thousands of deaths per year, depends on an enzyme called PI4K in the cells it infects. We will investigate a class of chemical compounds that can block PI4K to determine whether they could lead to a new class of drugs against HCV. We will also use these compounds to investigate how HCV makes copies of itself and how this process depends on the activity of PI4K.