Innate Control of Hepatitis C Virus Infection: Antiviral and Evasion Mechanisms

丙型肝炎病毒感染的先天控制：抗病毒和逃避机制

• 批准号: 7680865
• 负责人: FRANCIS VINCENT CHISARI
• 金额: $ 47.38万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7680865
• 关键词: Acute; Animal Model; Antiviral Agents; Biochemical; Carcinoma; Cell Line; Cells; Chronic; Chronic Hepatitis; Cleaved cell; Complement; Cultured Cells; Defense Mechanisms; Development; Disease; Double-Stranded RNA; Endopeptidases; Genes; Genome; Genotype; Goals; Hepatitis C; Hepatitis C virus; Hepatocyte; Human; Immune response; Infection; Interferons; Investigation; Knowledge; Lead; Life Cycle Stages; Liver; Liver Failure; Mediating; MicroRNAs; Microarray Analysis; Modeling; Molecular; Molecular Cloning; Outcome; Peptide Hydrolases; Persons; Primary carcinoma of the liver cells; Proteins; RNA Viruses; Reporting; Research; Series; Signal Pathway; Signal Transduction; Signaling Molecule; System; Therapeutic; Upper arm; Viral; Viral Proteins; Virus; Virus Replication; base; cellular targeting; hepatoma cell; insight; novel; novel therapeutics; pathogen; promoter; research study; response; virus development; virus host interaction

The long term goal of these studies is to define the innate host-virus interactions that occur during hepatitis C virus (HCV) infection with the hope that this will lead to novel therapeutic approaches to this disease. HCV is a noncytopathic, positive-strand RNA virus that causes acute and chronic hepatitis and hepatocellular carcinoma. Approximately 2-4 million persons are chronically infected by HCV in the USA and 170 million people are chronically infected worldwide, many of whom will die from liver failure and hepatocelluar carcinoma. The recent development of a robust cell culture model of HCV infection permits analysis of the entire HCV life cycle and facilitates analysis of the host-virus interactions that determine the outcome of HCV infection. Using that model we have recently shown that that the viral NS3/4A protease blocks double stranded (ds) RNA signaling and type 1 interferon (IFN) induction by cleaving a key intermediate in the dsRNA signaling pathway, and we discovered an entirely novel NS3/4A-independent mechanism whereby HCV evades the innate host response in infected cells. We also discovered that IFN rapidly modulates the expression of numerous cellular microRNAs (miRs) several of which have sequence-predicted targets within the HCV genome, that synthetic miR-mimics corresponding to several of these IFN-induced miRs reproduces the antiviral effects of IFN on HCV infection, and that neutralization of these miRs significantly reduces the antiviral effects of IFN against HCV. Finally, we showed that IFN inhibits the expression of the liver-specific miR-122 which is known to be essential for HCV replication. These findings identify a previously unsuspected effector arm of the innate host response that contributes to the control of HCV infection. In Specific Aim 1, we will use molecular and biochemical approaches to define the viral protein(s) that mediate NS3/4A-independent suppression of dsRNA-induced IFN expression (subaim 1a), identify the cellular dsRNA signaling molecule that is targeted by that (those) protein(s) (subaim 1b), and determine the molecular basis of this novel host evasion mechanism (subaim 1c). These results will enrich our understanding of the basis for viral persistence in HCV infection and, potentially, identify a previously unappreciated target(s) in HCV for the development of antiviral drugs. In Specific Aim 2, we will use microarray technology to define the full complement of cellular microRNAs that are regulated by type 1 and type 2 interferons in human liver cells (subaim 2a); determine whether any of these IFN-regulated miRs inhibit HCV infection (subaim 2b) and mediate IFN¿s antiviral effects (subaim 2c); and identify the viral and cellular targets of these miRs (subaim 2d), and the step(s) in the virus life cycle they interrupt when they inhibit HCV infection (subaim 2e). Collectively, these experiments will provide insight into an entirely new innate defense mechanism that protects the host against HCV infection and, potentially, lead to the development of novel antiviral strategies that exploit this mechanism to terminate chronic HCV infection.

这些研究的长期目标是确定丙型肝炎期间发生的先天宿主病毒相互作用 病毒（HCV）感染，希望这将为这种疾病带来新的治疗方法。丙肝病毒是一种 引起急性和慢性肝炎以及肝细胞性肝炎的非细胞病变性正链 RNA 病毒 癌。在美国，大约有 2-400 万人长期感染 HCV，其中 1.7 亿人 全世界范围内都有人被慢性感染，其中许多人会死于肝功能衰竭和肝细胞性肝癌 癌。最近开发的 HCV 感染的稳健细胞培养模型允许分析 整个 HCV 生命周期，并有助于分析决定 HCV 结果的宿主病毒相互作用 感染。使用该模型，我们最近表明病毒 NS3/4A 蛋白酶可阻断双链 (ds) RNA 信号传导和通过切割 dsRNA 信号传导中的关键中间体诱导 1 型干扰素 (IFN) 途径，我们发现了一种全新的 NS3/4A 独立机制，HCV 通过该机制逃避 受感染细胞的先天宿主反应。我们还发现 IFN 可以快速调节 许多细胞 microRNA (miR)，其中一些在 HCV 内具有序列预测的靶标 基因组，与这些 IFN 诱导的 miR 中的几个相对应的合成 miR 模拟物再现了 IFN 对 HCV 感染的抗病毒作用，并且这些 miR 的中和显着降低了抗病毒作用 IFN 对 HCV 的作用。最后，我们发现 IFN 抑制肝脏特异性 miR-122 的表达 已知这对于 HCV 复制至关重要。这些发现确定了一个以前未被怀疑的效应器 有助于控制 HCV 感染的先天宿主反应的一部分。在具体目标 1 中，我们将使用 分子和生化方法来定义介导 NS3/4A 独立的病毒蛋白 抑制 dsRNA 诱导的 IFN 表达 (subaim 1a)，鉴定细胞 dsRNA 信号分子 是那个（那些）蛋白质（subaim 1b）的目标，并确定这种新型宿主逃避的分子基础 机制（subaim 1c）。这些结果将丰富我们对丙型肝炎病毒持续存在基础的理解 感染，并有可能确定丙型肝炎病毒中以前未被认识的靶标，用于开发抗病毒药物 药物。在具体目标 2 中，我们将使用微阵列技术来定义完整的细胞 microRNA 受人肝细胞中 1 型和 2 型干扰素的调节 (subaim 2a)；确定是否有任何 这些 IFN 调节的 miR 抑制 HCV 感染 (subaim 2b) 并介导 IFN 的抗病毒作用 (subaim 2c)； 并确定这些 miR 的病毒和细胞靶标 (subaim 2d)，以及它们在病毒生命周期中的步骤 当它们抑制 HCV 感染时中断（subaim 2e）。总的来说，这些实验将提供对 一种全新的先天防御机制，可保护宿主免受 HCV 感染，并可能导致 开发利用这种机制来终止慢性丙型肝炎病毒感染的新型抗病毒策略。