Whole recombinant Hansenula polymorpha expressing hepatitis B virus surface antigen (yeast-HBsAg) induces potent HBsAg-specific Th1 and Th2 immune responses

摘要

Recent Studies have suggested that yeast cell wall components possess adjuvant activities In the present study, heat-killed whole recombinant Hansenula polymorpha yeast expressing hepatitis B Surface antigen (yeast-HBsAg) was generated, and the immune responses elicited by yeast-HBsAg were investigated in mice The studies showed that yeast-HBsAg as well as yeast greatly promotes the accumulation of immune cells in mouse spleen and contributes to the maturation of dendritic cells (DCs) Yeast-HBsAg not only induces significantly higher antibody responses (including IgG. IgG1 and IgG2a), but also increases the IgG2a/IgC1 ratio, while alum combined with HBsAg (HBsAg+alum) only enhances antibody responses, but not the IgG2a/IgG1 ratio compared to HBsAg alone Analysis of HBsAg-specific cytokines revealed that yeast-HBsAg is associated with production of both IFN-gamma and IL-4, but neither IFN-gamma not- IL-4 was detected in the HBsAg+alum-Immunized group Moreover, yeast-HBsAg induces potent HBsAg-specific lymphocyte proliferation and Cytotoxic Tlymphocyte(CTL)responses. In conclusion, yeast-HBsAg enhances both HBsAg-specific Th1 and Th2 immune responses. while alum only enhances Th2 Immune responses, suggesting that yeast-HBsAg may be an ideal candidate for an effective vaccine for the control of chronic hepatitis B virus (HBV) infection