Immunization with a Recombinant Expression Vector Encoding NS3/NS4A of Hepatitis C Virus Genotype 3a Elicits Cell-Mediated Immune Responses in C57BL/6 Mice.

Abstract Today, hepatitis C virus (HCV) infection is considered as one of the most significant international health concerns. Although novel therapeutic regimens against the infection have shown satisfactory results, no approved vaccine exists yet. This study aimed to evaluate the immunogenicity of a DNA vaccine candidate for HCV-3a, based on nonstructural proteins NS3/NS4A, in C57BL/6 mice. Immunogenicity effect of pDisplay-NS3/NS4A was analyzed through immunization with 100 and 200 μg concentrations of the construct with complete Freund's adjuvant, monophosphoryl lipid A (MPL), or without adjuvant. The frequencies of different splenic mononuclear cells were measured using the Mouse Th1/Th2/Th17 Phenotyping Kit. Moreover, the number of T-CD8+ cells was determined using conjugated anti-CD8a and anti-CD3e antibodies by flow cytometry. As observed, the frequencies of Th1, T-CD8+, and Th2 cells increased in all the experimental groups, compared with the controls. The highest levels of the respective cells we...