UV致弱尾蚴免疫对小鼠血吸虫再感染的保护力观察

目的观察致弱日本血吸虫尾蚴免疫小鼠再次感染血吸虫后的减虫率、减卵率及肝脏病理损伤，为血吸虫疫苗的研制奠定基础。方法分别以400μw／cm^2×60s和422μw／cm^2×40s两种不同UV强度及时间照射的日本血吸虫尾蚴免疫C57BL／6和DBA小鼠，观察免疫小鼠对再次血吸虫感染的减虫率、肝脏减卵率及肝脏病理改变。结果400μw／cm^2×60s（A）和422μw／cm^2UV×40s（B）照射的日本血吸虫尾蚴免疫组C57BL／6小鼠再次感染血吸虫后的减虫率分别为一0．60％和0．02％，肝脏肝脏减卵率分别为2．70％和11．37％；DBA小鼠再次感染血吸虫后的减虫率分别为29．10％和25．70％，肝脏肝脏减卵率分别为59．50％和69．50％。422μw／cm^2UV×40S辐照尾蚴免疫C57BL／6小鼠，再次感染血吸虫形成的肝脏单个虫卵肉芽肿面积与对照组比较显著减小（P〈0．01）；400μw／cm^2UV×60s和422μw／cm^2UV×40S辐照尾蚴免疫DBA小鼠再次感染血吸虫造成的肝脏单个虫卵肉芽肿面积与对照组比较显著减小（P〈0．01）。结论UV致弱尾蚴免疫对C57BL／6、DBA小鼠再次感染血吸虫的保护作用较小，但能降低肝脏卵荷并减轻肝脏的病理损伤。

UV-attenuated Schistosoma japonicum cercariae induce immune responses in mice that ameliorate liver damage during subsequent infection with normal cercariae

Objectives To investigate protection against schistosomiasis provided by UV-attenuated cercariae of Schistosoma japonicum in C57BL/6 and DBA mice. Methods Reductions in the worm burden as a result of attenuating cercariae with different UV intensities （A： μw/cm^2 UV for 1 min, B： 422 μw/cm^2UV for 40 sec） were evaluated in C57BL/6 and DBA mice. In addition, egg production and granuloma sizes were compared. Results C57BL/6 mice immunized with cercariae attenuated with 400 μw/cm^2 UV for 1 min had a reduced worm burden of -0.60% while similar mice immunized with cercariae attenuated with 422 μw/cm^2 UV for 40 sec had a reduced worm burden of 0.02%. The levels of egg reduction were 2.70% and 11.37%, respectively. Similarly immunized DBA mice had a reduced worm burden of 29.10% and 25.70%, respectively, and levels of egg reduction of 59.50% and 69.50%, respectively. A significant reduction in granuloma size was observed in C57BL/6 mice immunized with cereariae attenuated with 422 μw/cm^2 UV for 40 sec, in DBA mice immunized with cercariae attenuated with 400μw/cm^2 UV for 1 rain, and in DBA mice im munized with cercariae attenuated with 422 μw/cm^2UV for 40 sec. Conclusion UV-attenuated S. japonicum cereariae induced a low level of protection against Schistosoma japonicum and moderately reduced the granuloma size in C57BL/6 and DBA mice. Immunization with UV-attenuated S. japonicum cercariae induces an immune response in mice that amel- iorates liver damage during subsequent infection with normal eercariae.