摘要：采用HCV la／lb嵌合体cDNA构建表达质粒转染HepG2细胞，以免疫组化和Western blotting检测HCV蛋 白表达，RT-PCR检测HCV正、负链RNA，研究丙型肝炎病毒(HCV)la和lb型嵌合体全长cDNA在HepG2 细胞中的复制和表达。结果证明，转染细胞中检测到分子量约70kDa的HCVNS3蛋白，转染细胞连续传2O代，仍 能检测到HCV正、负链RNA。表明该HCV 嵌合体可以在细胞中复制和表达，HCV lb型的RNA依赖的RNA 聚合酶(RdRp)可以起始含la型非编码区的病毒复制。HCV 5 端非翻译区第11、12、13、34和35位核苷酸 改变可不影响其与核糖体结合。3 非翻译区9400，9403和9407位核苷酸改变，9435位缺失“A”，9409，9410 位及9495，9496，9497位分别插入“1Tr”和“AAT”可不影响RdRp的生物活性。本研究对阐明HCV复制和翻 译机制有重要意义。

Abstract：T0 investigate the replication and expression of Hepatitis C virus(HCV)1 a and lb chimeric cDNA in HepG2 cells．HCV l a／ l b chimeric CDNA was used to construct an expression plasmid for the tran sfection of HepG2 cells．HCV protein and HCV genomic RNA an d an ti—genomic RNA in the tran sfected HepG2 cells an d the culture supernatan ts were detected by immunocytochemical staining， W estern blotting an d RT．PCR respectively．T|le results showed that HCV NS3 protein with about 70kI)a was detectable in the tran sfected HepG2 cells．HCV genomic RNA and an ti—genomic RNA were found positive both in the HepG2 cells an d the culture supernatan ts for more than 20 generations．HCV la／lb chimera Can replicate an d express in HepG2 cells．suggesting that the RNA—dependent RNA polymerase (RdRp)of HCV lb Can initiate the replication of HCV containing genotype la untran slated region(UTR)． The alterations of 5 UTR of HCV lb at nucleotides ll，12，l 3，34 and 35 dO not influence its binding to ribo some．The 3 UTR at nucleotides 9400，9403 and 9407，the deletion ‘ at nucleotide 9439 an d insertions ‘1fr’an d ‘AAT’at nucleotides 9409，9410 and 9495，9496，9497，do not significan tly influence the RdRp binding an d activities of HCV lb．ThiS HCV chimeric cDNA Can be Of value in the studies of HCV replication an d expression．