Expression of hepatitis C virus cDNA in human hepatoma cell line mediated by a hybrid baculovirus-HCV vector.

Although great progress has been made in the characterization of the biochemical and biological features of hepatitis C virus (HCV) gene expression, the elucidation of the HCV life cycle and the evaluation of novel antiviral strategies have been hindered by the lack of a suitable cell culture system. In this context, the development of an efficient HCV cDNA delivery method would contribute to the understanding of HCV replication. To assess the functionality of baculovirus mediated gene delivery for HCV expression, we have constructed recombinant baculoviruses encoding HCV cDNA under the control of the cytomegalovirus promoter. Transduction of the human hepatoma cell line Huh-7 with Bac-HCV vectors was efficient and HCV cDNA expression was enhanced by treatment of the infected cells with dexamethasone. HCV structural and nonstructural polypeptides were processed correctly and were found to localize in the cytoplasm in a pattern characteristic of the endoplasmic reticulum. The expression of the HCV proteins was detected for 49 days after infection. Thus, these results indicate that the recombinant Bac-HCV vectors are a useful tool for the delivery of HCV cDNA and can facilitate the analysis of structural and functional properties of the HCV proteins. In addition, the Bac-HCV vectors can provide important information on the evaluation of novel anti-HCV antiviral strategies.