ABSTRACT
Objective To evaluate the immunogenicity and immunoprotective effect of heat shock protein 60 kDa (SjHSP60) of Schistosoma japonicum in mice after immunization and challenge infection, and explore the mechanism. Methods B cell/an?tibody?related databases and analysis tools were used to predict B?cell epitopes of SjHSP60. The mice were immunized with the recombinant SjHSP60 and challenged with S. japonicum cercariae. SjHSP60?specific antibodies in serum were detected by ELI?SA. The level of splenocyte proliferation was determined by 3H?TdR incorporation. Ex vivo suppression assay was performed to in?vestigate the effects of CD4 +CD25 + regulatory T cells (Tregs) induced by SjHSP60. Results SjHSP60 possessed multiple pre?dominant regions of B?cell epitopes. SjHSP60 induced a significant increase in both SjHSP60?specific IgG levels (P 0.05) and liver?accumulated eggs (P > 0.05) in S. japonicum?infected mice. Ex vivo assay showed that CD4+CD25+ Tregs from SjHSP60?immunized mice enhanced immunosuppressive activity. Conclusion SjH?SP60 has a dual role in host immune system, being involved in the induction of dominant humoral and cellular immune responses as well as in the enhancement of immunosuppression.