MOLECULAR BIOLOGY OF HEPATITIS C VIRUS

丙型肝炎病毒（HCV）是一种重要的人类病原体， 与输血相关的非甲非乙型肝炎（NANB）有关。 逆转录聚合酶法扩增丙型肝炎病毒RNA 链反应（cDNA PCR）是目前唯一实用的方法 以证明HCV感染患者的病毒血症。 然而，基因 不同HCV毒株之间的异质性导致假阴性结果 在cDNA PCR检测中，由于引物和模板错配， HCV账户 高达25%的社区获得性肝炎和超过90%的输血- 在美国的肝炎。 最近的克隆和 HCV基因组的测序导致了特异性 利用重组- 衍生的病毒抗原。 这些测试对于诊断和 筛查目的，但他们对HCV免疫力的了解很少， 因为目前可用的抗原是从HCV的部分表达的， 编码非结构蛋白或内部结构蛋白的基因组。 此外，HCV基因组遗传异质性的发现， 特别是在编码包膜蛋白的基因中，表明 可能是病毒包膜蛋白的异质性，类似于 人类免疫缺陷病毒。 这样的发现对于那些试图 在疫苗研发方面。 本项目的目标是：（1） 鉴定在cDNA PCR中具有低假阴性率引物组 （2）测定不同HCV基因组的核苷酸序列;和 (3)分析用HCV感染灵长类动物是否诱导保护性 免疫力

Hepatitis C virus (HCV) is an important human pathogen that is strongly associated with transfusion related non-A, non-B (NANB) hepatitis. Amplification of HCV RNA sequences by reverse transcription and polymerase chain reaction (cDNA PCR) is the only practical method currently available to demonstrate viremia in patients with HCV infection. However, genetic heterogeneity among different HCV strains results in false negative results in cDNA PCR assays because of primer and template mismatch. HCV accounts for up to 25% of community-acquired hepatitis and over 90% of transfusion- associated hepatitis in the United States. The recent cloning and sequencing of the genome of HCV led to the development of specific serologic tests for antibody to HCV (anti-HCV) that utilized recombinant- derived viral antigens. These tests have been useful for diagnostic and screening purposes but they shed little light on immunity to HCV, in part because currently available antigens are expressed from parts of the HCV genome that encode nonstructural or internal structural proteins. Furthermore, the finding of genetic heterogeneity of the HCV genome, especially in the gene encoding the envelope proteins, suggests that there may be heterogeneity of viral envelope proteins similar to that seen in human immunodeficiency viruses. Such a finding would bode ill for attempts at vaccine development. The objectives of this project are to: (1) identify primer sets that have a low false negative rate in a cDNA PCR assay; (2) determine the nucleotide sequence of diverse HCV genomes; and (3) analyze whether infection of primates with HCV induces protective immunity.