紫外线照射前后日本血吸虫尾蚴抗原的初步分析

Preliminary study of cercaria antigen of Schistosoma japonicum before and after ultraviolet irradiation

目的探讨日本血吸虫尾蚴经紫外线(UV)照射后抗原成分的改变。方法日本血吸虫尾蚴经UV(400 μW/cm2)照射1 min 后,取其可溶性抗原经照射尾蚴抗原(UVCA)与未经照射的尾蚴可溶性抗原(NCA)同步进行SDS-PAGE和免疫印迹试验。结果经UV照射后,日本血吸虫尾蚴新出现了Mr 212 000和82 000抗原带,Mr 116 000、26 000和16 000抗原带浓度明显升高;NCA的Mr 67 000分子仅能被UVCA免疫猪血清识别,而不能被感染猪血清识别,Mr 79 000和94 000与免疫猪血清的反应也明显强于感染猪血清。结论UV照射后新出现或含量增加的抗原成分以及仅免疫猪血清所识别的抗原分子可能是照射尾蚴激发高度保护性免疫的主要因素。

Objective To study the changes in the constituents of the cercaria antigen of Schistosoma japonicum before and after ultraviolet irradiation. Methods The cercaria of Schistosoma japonicum were exposed to ultraviolet light (UV) irradiation at a dose of 400 μW/cm 2 for 1 min, and the UV-irradiated cercaria antigen (UVCA) and normal cercaria antigen (NCA) were simultaneously analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Results At least 2 antigens with relative molecular mass (M r ) of 212 000 and 82 000 were identified in UVCA but not in NCA by SDS-PAGE analysis, and the concentrations of the antigens with M r of 116 000, 26 000 and 16 000 in UVCA were significant higher than those in NCA. On the other hand, the antigenic molecule with M r of 67 000 in NCA was recognized by serum from pigs vaccinated with UV-attenuated cercariae, but not by serum from pigs with Schistosoma japonicum infection. Antigens with M r of 79 000 and 94 000 were apparently more strongly reactive with the former porcine serum than with the latter. Conclusion The results suggest that all the novel antigens arising from or increased by UV exposure, or antigens specifically recognized by serum from pigs vaccinated by UV-attenuated carcariae may be the principal factors in the highly protective immunity provoked by irradiated cercariae.