Abstract: 　AIM: To compare the differences in the protective immune response induced by reSjc26GST between C57BL/6 and BALB/c mice. METHODS: Mice were immunized subcutaneously with reSjc26GST emulsified with Freund’s adjuvant. The specific antibody isotypes elicited by reSjc26GST, in vitro lymphocyte proliferation and cytokine responses to reSjc26GST were examined. RESULTS: The level of anti reSjc26GST IgG was higher in immunized C57BL/6 mice than in BALB/c mice, and examination of the IgG subclasses demonstrated that reSjc26GST immunized C57BL/6 mice resulted in predominantly IgG1 and IgG2a/IgG2b antibody responses, whereas in BALB/c mice, IgG1 antibody. Cytokine production assays revealed that the quantity of IFN γ and IL 2 and IL 5 released from the reSjc26GST primed splenocytes were significantly higher in C57BL/6 mice than in BALB/c mice. These results showed that the immunization with reSjc26GST in C57BL/6 mice elicited a mixed immune reaction of Th1 and Th2 cell responses as demonstrated by the elevated levels of IgG1, IgG2a/IgG2b and IL 2, IFN γ,IL 5 , whereas in BALB/c mice, reSjc26GST immunization elicited Th2 response as demonstrated by the elevated levels of IgG1, IL 2 and IFN γ. CONCLUSION: Immunization with reSjc26GST could elicit higher humoral and cellular immune responses in C57BL/6 mice than in BALB/c mice.

Key words: Schistosoma japonicum, recombinant Sjc26GST, immune response