日本血吸虫云南品系SIEA对小鼠感染皖鄂品系血吸虫的免疫保护作用

目的观察日本血吸虫云南品系未成熟卵可溶性抗原SIEA免疫小鼠后攻击感染皖鄂品系血吸虫尾蚴，是否也能诱导出免疫保护效果。方法20只ICR小鼠随机分为免疫组和对照组，经日本血吸虫云南品系SIEA免疫后攻击感染皖鄂品系血吸虫尾蚴，感染后46d观察减虫率、粪卵减少率、雌虫子宫内虫卵数、肝表面虫卵结节数、肝脏各期虫卵数及各期虫卵构成比。结果SIEA免疫后粪卵及雌虫子宫内虫卵减少率分别为34．45％，23．69％（P〈0．05）；肝表面虫卵结节密度下降29．03％（P〈0．05）；肝组织内虫卵减少29．07％（P〈0．05），成熟虫卵减少48．41％（P〈0．05）。肝组织内成熟虫卵比例下降，未成熟卵比例增加（P〈0．05）。结论日本血吸虫（云南品系）未成熟卵可溶性抗原（SIEA）的抗原性较强，小鼠经云南品系SIEA免疫后攻击感染皖鄂品系血吸虫尾蚴也诱导小鼠产生了抗卵胚发育及抗雌虫生殖免疫力，结果提示将来在中国大陆使用SIEA疫苗时，似可不必考虑血吸虫品系的影响。

IMMUNE PROIF_L-~ON IN MICE PROVIDED BY SIEA OF A YUNNAN ISOLATE OF SCHISTOSOMA JAPONICUM BUT CHALLENGED WITH ANOTHER ISOLATE

Objective To observe the protective effect induced by soluble immature egg antigen （SIEA） of a Yunnan isolate of Schistosoma japonicum in mice challenged with a Wan＇e isolate. Methods Twenty ICR mice were immunized with SIEA of the Yunnan isolate of S. japonicum hut were challenged with cercariae of the Wan＇e isolate. On day 46 after infection, mice were sacrificed and different indices were compared with those from the control group. The indices includ- ed worm reduction, the rate of egg reduction in feces, the female uterus, and the liver, the number of egg nodes on the liver surface, and proportion of eggs in different stages in the liver. Results The rate of egg reduction was 34.45% in feces and 23.69% in the female uterus （P〈0.05）. The number of egg nodes on the liver surface decreased by 29.03%（P〈0. 05）. The total egg count in the liver decreased by 29.07% per female （P〈0.05）. The mature egg counts in the liver decreased by 48. 41%（P〈0.05） per female. The proportion of immature eggs increased and that of mature eggs decreased （P〈0.05） . Conclusion SIEA has strong antigenicity and anti-fecundity, anti-embryonation immunity are induced in mice immunized with SIEA of the Yunnan isolate of S. japonicurn but challenged with the Wan＇e isolate. In all likelihood, the difference between isolates may not be taken into account when using SIEA vaccination in the Chinese mainland.