ABSTRACT
Objective To investigate the development strategy of novel T cell based vaccine against HCV infection.Methods BALB/c mice were primed with pSCK-based DNA vaccine and boosted with type 5 adenoviral vector-based vaccine, which expressed the structural proteins ( Core, E1 and E2) de-rived from a Chinese HCV patient (genotype 1b, Hebei strain).Enzyme linked immunospot assay (ELIS-POT) and intracellular cytokine staining ( ICS) were used to analyze the elicited antigen-specific immune re-sponses and the efficacy of cross-protection.Results Immunization of mice with the prime-boost vaccination strategy elicited stronger T cell immune responses against multiple HCV antigens than using the DNA vac-cines alone, especially the IFN-γ-secreting T cell responses against E1 protein as indicated by ELISPOT as-say.ICS data indicated that the prime-boost regimen elicited more TNF-α-producing CD4+and IFN-γ-produ-cing CD8+T cells against E1 protein and high levels of IFN-γ-producing CD4+and CD8+T cells against E2 protein in comparison with immunization with DNA vaccines.Moreover, the prime-boost vaccination was ca-pable of eliciting effective cross-protection in a surrogate challenge model based on a recombinant heterolo-gous HCV (JFH1, 2a) vaccinia virus.Conclusion The prime-boost vaccination using DNA and rAd5-based vaccine expressing HCV structural antigens induced significant cellular immune response and cross-protection in mice, suggesting the possibility of using it as a promising T cell based vaccine against HCV in-fection.