Immunogenicity and protective effect induced by co-immunization with HCV recombinant protein antigens / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the cellular and humoral immune responses and protective effect induced by co-immunization with two multi-epitope combinant antigens. Methods Mice were co-im-munized with the muhi-epitope HCV-T and HCV-E1 antigens three times. Sera antibodies IgG, IgG1 and IgG2a were tested by ELISA. Spleens from BALB/c mice immunized were removed 10 days after the last im-munization. CTL activity was assessed using LDH cytotoxicity assay kit. IFN-γ- and IL-4-secreting cells were quantified using ELISPOT kit. Two weeks after the final immunization, the mice were challenged sub-cutaneously(s, c. ) at the back with 106 SP2/0-NS3 cells, and protective effect was observed. For therapy, 106 SP2/0-NS3 cells were implanted into the back of BALB/c mice. Seven days later, mice were immuniza-tion three times. Therapy effect was observed. Results Co-immunization with HCV-T and HCV-E1 induced high tiers of HCV-El-specific IgG, IgG1 and IgG2a antibodies, and high level of CTL activity. Synergistic effect in frequencies of both specific IFN-γ-secreting cells and IL-4-secreting cells was observed in mice co-immunized. Prophylactic as well as therapeutic administration of mT + mE1 in mice led to protecting mice against SP2/0-NS3 cells. These results suggested that mT + mE1 was potential as a prophylactic as well as therapeutic HCV vaccine. Conclusion Co-immunization with HCV-T + HCV-EI induced protective humor-al and cellular immune response. HCV-T + HCV-E1 was potential as a recombinant HCV vaccine.