[Immune responses to recombinant expression plasmid encoding hepatitis C virus core antigen].

OBJECTIVE

To study the feasibility of DNA immunization with recombinant expression plasmid containing hepatitis C virus (HCV) core gene against HCV infection.

METHODS

The recombinant plasmid containing HCV C gene was constructed and expressed transiently by using lipofectamine in the mouse SP2/0 cells. After appraisal and purification, these plasmid and control DNA were directly injected intramuscularly into BALB/c mice, HCV C specific antibody in the sera was checked with ELISA. Proliferative responses of spleen cells from experimental and control mice were determined by (3)H thymidine incorporation and cytotoxicity T lymphocyte (CTL) activity was measured by standard 4-h (51)Cr release assays.

RESULTS

All immunized mice developed anti-HCV core antibodies and this antibody was dose and immune number dependent. Lymphoproliferative responses for HCV core antigen were higher in immunized mice than in control mice (P < 0.05), stimulation indices (SI) were 2.42 - 6.10. CTLs might induce approximately 63.13% lysis of pcDNA HCV C transfected SP2/0 target cells.

CONCLUSION

It is suggested that HCV C gene immunization is a promising method of vaccination against HCV infection.