Induction of IFN-γ cytokine response against hepatitis B surface antigen using melittin

AIM: In this study we co-administered melittin along with HBsAg/alum vaccine to investigate if it helps elicitation of Th1/Th2 response. BACKGROUND: Hepatitis B virus (HBV) infection is a life-threatening liver infection, which can lead to chronic liver disease. Vigorous T cell responses are stimulated at acute, self-limiting HBV infection, while chronic HBV infection elicits very weak T cell responses. The prevalence of HBV infection has been decreased by the approved vaccination approach using recombinant HBs antigen (HBsAg) and alum i.e. HBV vaccine. Alum, a strong Th2 stimulator, is usually used as adjuvant to increase HBsAg immunogenicity. The present vaccine does not induce protective and/or prophylactic immune response in some groups. Melittin, major active component in the venom of honeybee, induces Th1 development. PATIENTS AND METHODS: Experimental mice were immunized with melittin plus hepatitis B vaccine on day 0 following by two booster doses with the same injections. Lymphocyte proliferation, IFN-γ, and IL-4 level, total antibody and isotyping of IgG1, IgG2a IgG2b, and IgM were measured using ELISA. RESULTS: Administration of melittin and HBV vaccine had no effect on lymphoproliferation and total antibody responses, but increased IFN-γ response and induced Th1 response. CONCLUSION: The present study proposed that administration of melittin along with conventional vaccine shifts T cell responses towards Th1/Th2 dominated with Th1 response. The resultant immune response leads to activation of both cell-mediated and humoral immune responses, both of which required for clearance of HBV infection.