Host and viral determinants of hepatitis C virus macaque infection

 描述(申请人提供)：丙型肝炎病毒(丙型肝炎病毒)是西半球肝癌的主要原因。超过1.7亿人感染了这种病毒，因此肝损伤和癌症的风险增加。要了解这种病毒如何导致肝病和开发急需的疫苗，需要有一个具有免疫能力的丙型肝炎病毒动物模型。丙型肝炎病毒领域的教条是，这种病毒只感染人类和黑猩猩。由于美国国立卫生研究院最近暂停了对黑猩猩的研究，有效地禁止了这些动物的使用，迫切需要一种替代的具有免疫能力的丙型肝炎病毒动物模型。为了探索小型灵长类动物是否可以支持丙型肝炎病毒的感染，我们从辫尾猕猴(Macaca nomestrina，MN)诱导的多能干细胞来源的肝细胞中培养出肝细胞。令人惊讶的是，这些细胞支持可检测到的细胞感染水平 培养衍生出2a型丙型肝炎病毒。我们发现，猕猴版本的丙型肝炎病毒受体CD81的低效功能限制了这些细胞的丙型肝炎病毒感染。一种可以使用来自多种物种的CD81蛋白的突变型2a病毒克服了这一障碍，并有效地感染了猕猴肝细胞。我们最近有了一个惊人的发现，这种病毒的野生型和突变型都可以在体内感染猪尾猕猴，从而首次证明了丙型肝炎病毒可以在人类和黑猩猩以外的动物中复制。在这项拨款中，我们建议进行实验，以进一步确定猕猴感染丙型肝炎病毒的特征。这将包括确定恒河猴是否也可以感染2a型丙型肝炎病毒。恒河猴比猪尾猕猴更容易获得，也可以获得比猪尾猕猴更多的物种特异性试剂。我们还将检查猕猴感染丙型肝炎病毒的病毒决定因素。我们将探索病毒如何适应在这种宿主上更有效地复制的机制，并确定我们是否能够扩大感染NHP的病毒分离株的范围。最终，我们的研究将提供第一个具有免疫能力的易处理的动物模型，为探索丙型肝炎病毒在体内的复制和发病机制建立新的途径，最终目标是开发针对这种病毒的有效疫苗。

 DESCRIPTION (provided by applicant): The hepatitis C virus (HCV) is the leading cause of liver cancer in the Western Hemisphere. Over 170 million people are infected with this virus and consequently at increased risk of liver damage and cancer. Understanding how this virus induces liver disease and the development of a much-needed vaccine requires an immunocompetent HCV animal model. The dogma in the HCV field was that this virus only infects humans and chimpanzees. As a recent NIH moratorium on chimpanzee research has effectively prohibited use of these animals, an alternative immunocompetent HCV animal model is desperately needed. To explore if small primates can support HCV infection, we generated hepatocytes from pigtail macaque-(Macaca nemestrina, Mn) induced pluripotent stem cell-derived hepatic cells. Surprisingly, these cells supported detectable levels of infection with cell culture derive genotype 2a HCV. We found that inefficient function of the macaque version of the HCV receptor, CD81, limited HCV infection of these cells. A mutant genotype 2a virus that can use CD81 proteins from a wide range of species overcame this block and efficiently infected the macaque hepatocytes. We have recently made the startling discovery that both wild type and mutant versions of this virus could infect pigtail macaques in vivo, thus demonstrating for the first time that HCV can replicate in animals other than humans and chimpanzees. In this grant we propose experiments to further characterize macaque HCV infections. This will include determining if rhesus macaques, which are more readily available and a larger set of species-specific reagents than pigtail macaques are obtainable, can also be infected with genotype 2a HCV. We will also examine the viral determinants for HCV infection of macaques. We will explore mechanisms by which virus can adapt to more efficiently replicate in this host and determine if we are able to expand the range of viral isolates that can infect NHPs. Ultimately, our studies will provide the first immunocompetent tractable animal models that will establish new avenues to explore HCV replication and pathogenesis in vivo with the eventual goal of developing efficacious vaccine against this virus.