[Shistosoma japonicum: dynamics of cytokine production induced by immunization of mice with recombinant GST-Sj32 protein before and after challenge infection].

Aim: To explore the mechanism of protective immunity of rGST-Sj32.

Methods: BALB/c mice were immunized subcutaneously with rGST-Sj32 emulsified with Freund's complete adjuvant. Five mice from each group were killed prior to immunization, prior to challenge and 10 days, 30 days and 45 days post-challenge, respectively. Spleen cells from these mice were cultured and levels of cytokine secreted by splenocytes were detected by ELISA.

Results: Compared with the control group, the quantity of IL-4, IL-5 and IFN-gamma released from rGST-Sj32-primed splenocytes were increased to varying degrees, being (10.21+/-3.65) ng/L, (19.89+/-9.57) ng/L and (5.09+/-2.51) microg/L, respectively. The level of IFN-gamma post challenge did not increase in control group and immunization group. The levels of IL- 4 and IL-5 in the control group were elevated gradually following challenge, and were much higher than those in immunization group.

Conclusion: The immunization with rGST-Sj32 elicited mainly a Th1 type immune response in BALB/c mice, whereas the immune response induced by challenge was a Th2 type.