Prophylactic DNA vaccine for hepatitis C virus (HCV) infection: HCV-specific cytotoxic T lymphocyte induction and protection from HCV-recombinant vaccinia infection in an HLA-A2.1 transgenic mouse model

摘要

DNA vaccines express antigens intracellularly and effectively in- duce cellular immune responses. Because only chimpanzees can be used to model human hepatitis C virus (HCV) infections, we developed a small-animal model using HLA-A2.1-transgenic mice to test induction of HLA-A2.1-restricted cytotoxic T lymphocytes (CTLs) and protection against recombinant vaccinia expressing HCV-core. A plasmid encoding the HCV-core antigen induced CD8~+ CTLs specific for three conserved endogenously expressed core peptides presented by human HLA-A2.1. When challenged, DNA- immunized mice showed a substantial (5-12 log_10) reduction in vaccinia virus titer compared with mock-immunized controls. This protection, lasting at least 14 mo, was shown to be mediated by CD8~+ cells. Thus, a DNA vaccine expressing HCV-core is a potential candidate for a prophylactic vaccine for HLA-A2.1~+ humans.