Before the start of the schistosomiasis transmission season, 129 villagers resident on a Schistosoma japonicum-endemic island in Poyang Lake, Jiangxi Province, 64 of whom were stool-positive for S. japonicum eggs by the Kato method and 65 negative, were treated with praziquantel. Forty-five days later the 93 subjects who presented for follow-up were all stool-negative. Blood samples were collected from all 93 individuals. S. japonicum soluble worm antigen (SWAP) and soluble egg antigen (SEA) stimulated IL-4, IL-5 and IFN-γ production in whole-blood cultures were measured by ELISA. All the subjects were interviewed nine times during the subsequent transmission season to estimate the intensity of their contact with potentially infective snail habitats, and the subjects were all re-screened for S. japonicum by the Kato method at the end of the transmission season. Fourteen subjects were found to be infected at that time. There was some indication that the risk of infection might be associated with gender (with females being at higher risk) and with the intensity of water contact, and there was evidence that levels of SEAinduced IFN-γ production were associated with reduced risk of infection.

Schistosome antigen-driven cytokine responses and antischistosome antibody levels of residents of a Schistosoma japonicum endemic island in Poyang Lake, Jiangxi Province were studied before and 45 days after treatment with praziquantel. IL-4, IL-5, IL-10 and INF-g were all detected in the supernatants of whole-blood cultures after stimulation with schistosome soluble egg antigen (SEA) and soluble worm antigen preparation (SWAP). The percentages of subjects producing detectable amounts of each cytokine assayed were higher in the group who were negative by stool examination at the start of the study than in those who were initially stool positive. After praziquantel treatment the percentages of subjects producing both type I and type II cytokines increased. This suggests that the production of both types of cytokine was down-regulated in the presence of live, egg-laying S. japonicum adult worms but that this was reversible by treatment. In contrast, the antibody studies showed higher levels of SWAP and SEA-specific antibodies (IgE, total IgG, IgG4, IgM) in subjects who were originally stoolpositive than in those who were stool-negative. After treatment specific IgE responses were elevated, but total IgG and IgG4 anti-SEA and IgM anti-SWAP antibody levels all fell significantly.

为探索日本血吸虫（中国大陆株）22.6kDa抗原（Sj22.6）编码基因用作核酸疫苗的可行性，将pCMV/Sj22.6基因重组质粒经肌肉注射免疫了一批BALB/c小鼠并进行攻击感染试验，结果表明此重组质粒能在小鼠体内持续存在、稳定表达并诱导小鼠产生特异性的抗Sj22.6抗体，但未能诱导有效的保护力。

目的：大量获得纯化的日本血吸虫22.6kDa重组抗原。方法：用PCR方法将其编码基因序列经改造后亚克隆入载体质粒pGEX-1λT进行表达。结果：得到了融合表达的蛋白抗原。此融合蛋白表达量大，用凝血酶酶切后易大量制备纯化的重组22.6kDa抗原。结论：以此融合蛋白免疫的小鼠抗血清进行免疫印迹试验，表明Sj22.6/Sj26GST融合重组蛋白具有与Sj22.6蛋白一样的免疫学活性。