Cyclosporine, Cyclophilins and HCV Replication

环孢素、亲环素和 HCV 复制

• 批准号: 8120232
• 负责人: HENGLI TANG
• 金额: $ 32.13万
• 依托单位: FLORIDA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-04 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8120232
• 关键词: Acute; Address; Affinity; Antiviral Agents; Binding; Biochemical; Biological Assay; Biological Models; C-terminal; Cell Communication; Cell Culture Techniques; Cells; Chronic; Clinical; Clinical Treatment; Clinical Trials; Complex; Cyclophilin A; Cyclophilins; Cyclosporine; DNA-Directed RNA Polymerase; Data; Dependence; Development; Diagnostic; Drug resistance; Ensure; Face; Fibrosis; Genotype; Goals; Health; Health system; Hepatitis C; Hepatitis C virus; Human; Human Virus; In Vitro; Infection; Infection prevention; Interferons; Intervention; Knowledge; Lead; Liver Cirrhosis; Liver diseases; Maps; Mediator of activation protein; Messenger RNA; Molecular; Molecular Biology Techniques; Molecular Chaperones; Mutagenesis; Mutation; Nonstructural Protein; Parasites; Pathway interactions; Patients; Pharmaceutical Preparations; Play; Population; Primary carcinoma of the liver cells; Proteins; RNA Binding; Research; Resistance; Role; Small Interfering RNA; Surface; Testing; Therapeutic; Thumb structure; Vaccines; Variant; Viral; Viral Genome; Virus; Virus Replication; Work; anti-hepatitis C; base; cofactor; drug candidate; global health; hepatoma cell; in vivo; insight; interferon therapy; mutant; new therapeutic target; novel; pathogen; positional cloning; prevent; programs; prophylactic; protein function; replicase; research study; resistant strain; viral RNA; viral resistance

DESCRIPTION (provided by applicant): The broad, long-term goal of our program is to advance the knowledge of virus-host cell interactions by characterizing cellular cofactors essential for hepatitis C virus (HCV) infection. HCV infects 170 million people worldwide and is major cause of hepatocellular carcinoma. Understanding how this virus interacts with the host is of critical importance to the development of diagnostics, antiviral drugs, and a prophylactic vaccine. Our previous studies demonstrated that HCV infection of cultured hepatoma cells is critically dependent on a cellular protein, cyclophilin A (CyPA), and that ablating the function of this protein can not only prevent new infections but also suppress an existing infection. In addition, CyPA is a principal mediator of HCV resistance to cyclosporine A (CsA) and its derivatives, which inhibit HCV replication with an undefined mechanism and are currently being evaluated in clinical trials as candidate anti-HCV drugs. The experiments proposed here will investigate the molecular mechanisms that determine the essential cofactor function of CyPA, the action of CsA, and the related CsA resistance. The following experiments will be performed: (1) CsA and small interfering RNA directed at CyPA mRNA will be used to identify the specific function of HCV replicase that requires CyPA as a cofactor. A detailed understanding of why and where the virus needs this cellular chaperone to survive will offer new perspectives on the replication strategy of HCV. (2) Biochemical assay and mutagenesis will be used to characterize the critical interaction between CyPA and the viral replicase, which represents a novel structural interface of virus-host cell interaction that may be disrupted for therapeutic purposes. (3) Macromolecular interaction and reverse genetics will be employed to dissect the mode of action for CsA and molecular basis of CsA resistance with the ultimate goal of predicting and circumventing that resistance. The results of the proposed studies will not only provide significant insights into how highly successful parasites such as human viruses hijack host cell machineries to replicate efficiently but also reveal new therapeutic targets for antiviral intervention. PUBLIC HEALTH RELEVANCE: Hepatitis C virus (HCV) infects 3% of the world's population and cause fibrosis, liver cirrhosis and hepatocellular carcinoma (HCC). No prophylactic vaccine exists, and both the current treatment and the drugs in the development pipeline face serious drug-resistance issues. The proposed research will illustrate the molecular basis of drug resistance for a new drug candidate and may also identify a novel aspect of virus-host cell interaction than can serve as target for a new class of drugs.

描述（由申请人提供）：我们程序的广泛长期目标是通过表征对丙型肝炎病毒（HCV）感染必不可少的细胞辅助因子来提高病毒宿主细胞相互作用的知识。 HCV在全球范围内感染了1.7亿人，是肝细胞癌的主要原因。了解该病毒与宿主如何相互作用对于诊断，抗病毒药和预防性疫苗的发展至关重要。我们以前的研究表明，培养的肝癌细胞的HCV感染在严重取决于细胞蛋白，环磷脂A（CYPA），并且消融该蛋白质的功能不仅可以防止新的感染，还可以抑制现有的感染。此外，CYPA是对Cyclosporine A（CSA）及其衍生物的HCV耐药性的主要介体，它抑制了HCV复制，并以不确定的机制抑制了HCV复制，目前正在临床试验中评估作为候选抗HCV药物。这里提出的实验将研究确定CYPA的必需辅因子功能，CSA的作用以及相关的CSA耐药性的分子机制。将进行以下实验：（1）针对CYPA mRNA的CSA和小型干扰RNA将用于识别需要CYPA作为辅因子的HCV复制酶的特定功能。对病毒需要这种细胞伴侣生存的原因和何处的详细理解将为HCV的复制策略提供新的观点。 （2）生化测定和诱变将用于表征CYPA与病毒复制酶之间的临界相互作用，该酶是病毒宿主宿主相互作用的新结构界面，可能会被破坏以用于治疗目的。 （3）将采用大分子相互作用和反向遗传学来剖析CSA的CSA和CSA抗性分子基础的作用方式，以预测和避免这种抗性的最终目标。拟议的研究的结果不仅将提供有关诸如人类病毒等非常成功的寄生虫如何有效复制宿主的寄生虫如何有效复制的，而且还揭示了抗病毒干预的新治疗靶标。公共卫生相关性：乙型肝炎病毒（HCV）感染了世界人口的3％，并引起纤维化，肝硬化和肝细胞癌（HCC）。不存在预防性疫苗，并且目前的治疗和开发管道中的药物都面临严重的抗药性问题。拟议的研究将说明新药候选药物耐药性的分子基础，并且还可以确定病毒宿主细胞相互作用的新方面，而不是作为新药物的靶标。