Abstract: AIM:To detect the protective effect of cellular immunity induced by schistosomal
vaccine.METHODS:Mice were vaccinated with300 UV- attenuated cercariae or infected with 25
cercariae of Schistosoma japonicum. The spleen cells and peritoneal exudate macrophages (Mφ)
were stimulated in vitro with parasitic antigen(SWAP and SEA) or mitogen(ConA or LPS) at wk2,4,8 and 12, and the dynamic changes of splenic T cell proliferation and activity of interlukin-1 (IL- 1 ) production by Mφand activity of IL- 2 production by splenic T cells were observed. RESULTS: T lymphocyte proliferation in response to SWAP or SEA was significantly enhanced in both groups at wk 2 - 8 post-vaccination or post-infection, and markedly depressed at wk 12. The activity of I-1 and IL-2 elicited by SWAP or SEA in vaccinated group peaked at wk 4 and declined thereafter. In the infected group , SWAP triggered IL-1 and IL-2 production peaked at wk 8- 12 and wk 12 respectively. CONCLUSION: It is suggested that the cellular immune response ( including T lymphocyte proliferation and cytokine production) might play an important role in protective immunity to S.japonicum.

Key words: Schistosoma japonicum, UV-attenuated cercariae, T lymphocyte proliferation, IL- 1, IL- 2