A vaccinia replication system for producing recombinant hepatitis C virus

Abstract

Aim: To develop a cell culture system capable of producing high titer hepatitis C virus (HCV) stocks with recombinant vaccinia viruses as helpers. Methods: Two plasmids were used for the generation of recombinant HCV: one containing the full-length HCV cDNA cloned between T7 promoter and T7 terminator of pOCUS-T7 vector, and the other containing the HCV polyprotein open reading fame (ORF) direct1y linked to a vaccinia late promoter in PSC59. These two plasmids were co-transfected into BHK21 cells, which were then infected with vTF7-3 recombinant vaccinia helper viruses. Results: After 5 d of incubation, approximately 3.6×107 copies of HCV RNA were present per milliliter of cell culture supernatant, as detected by fluorescence quantitative RT-PCR (FQ-PCR). The yield of recombinant HCV using this cell system increased 100- to 1 000- fold compared to in vitro-transcribed HCV genomic RNA or selective subgenomic HCV RNA molecule method. Conclusion: This cell culture system is capable of producing high titer recombinant HCV. Copyright © 2004 by The WJG Press.