A single immunization with a plasmid encoding hepatitis C virus (HCV) structural proteins under the elongation factor 1-α promoter elicits HCV-specific cytotoxic T-lymphocytes (CTL)

Abstract

Recent studies have raised the possibility that DNA-based vaccination may prove useful for generating virus-specific cytotoxic T-lymphocytes (CTL) responses. Recently, a plasmid containing the human elongation factor 1α(EF1-α) promoter, pEF321, was reported to be a versatile expression vector for gene expression in mammalian cells in vitro. In the present study, we assessed the capability of a novel plasmid, pEFCE1E2, encoding hepatitis C virus (HCV) structural proteins (core, E1 and E2) under the EF1-α promoter to generate CTL against HCV in vivo. BALB/c mice were immunized with the pEFCE1E2 but not with a plasmid possessing the same cDNA under the cytomegalovirus developed HCV-specific effector cells by a single immunization. These effector cells elicited by pEFCE1E2 immunization were CD8 + and major histocompatibility complex class I restricted. These studies provided evidence for the potential utility of the EF1-α promoter for development of DNA vaccines against HCV infections.