Protection of infection using monoclonal antibody produced by Schistosoma japonicum cercariae attenuated by ultra violet-irradiation.

用经254 nm紫外线照射致弱的日本血吸虫尾蚴免疫BALB/c小鼠。以500 mW/cm~2·cm~2·s~(-1)紫外线照射的尾蚴免疫保护率最高，为47.3%。用紫外线致弱的尾虫免疫小鼠，融合小鼠的脾细胞，制备出单抗。筛选出12株免疫荧光法识别血吸虫24小时幼虫表面的单抗，并检测其与各虫期的反应性。用这12株McAb对肺血吸虫和肝脏中未成熟虫体的抗原相似性进行了检测。这两个阶段的表面都被7个McAb识别，而都不被1个McAb识别，因此两者是接近的。然而，肺血吸虫的抗原性略有不同，因为它们不能被识别肝脏中未成熟虫子的3株McAb识别。用4株识别肺血吸虫表面的McAb对小鼠进行了免疫保护试验，其中2株McAb的保护率较高，分别为21.2%和18.0%，与成虫被膜、成虫实质和虫卵均有较强的结合力。体外实验检测McAb对血吸虫幼虫的杀伤作用。它们被带有McAb的小鼠中性粒细胞破坏和杀死，McAb结合在成虫表面，并补充补体。由于这些有效的McAb识别分布在成虫实质和表面的共同表位，因此建议用成虫代替血吸虫作为获得抗原的材料，以诱导保护性免疫。

BALB/c mice were immunized with cercariae of Schistosoma japonicum attenuated by irradiation with ultra violet ray at 254 nm. The highest protection attained was 47.3% by immunization with cercariae irradiated by UV at 500 mW sec/ <cm^2> . Mice were immunized with UV-attenuated cercariae and monoclonal antibodies (McAb) were produced by fusion of spleen cells from these mice. Twelve McAb, which recognized the surface of 24 hour-schistosomula by immunofluorescence, were selected and examined for reactivity to all stages of worms. Using these 12 McAb, antigenic similarity was examined between lung schistosomula and immature worms in the liver. Both were found to be close since the surface of both stages was recognized by 7 McAb and both were not by 1 McAb. The lung schistosomula, however, had a slightly different antigenicity because they were not recognized by 3 McAb which recognized immature worms in the liver. Protection of infection was examined in mice by injectng ascitic fluid of 4 McAb which recognized the surface of lung schistosomula, and 2 McAb showed comparatively high protection rates at 21.2 and 18.0%, respectively, and bound strongly to the tegument of adult and also to the parenchyma of adult worms and the egg. The killing effect of McAb on schistosomula was examined in vitro. They were damaged and killed by mouse neutrophils with the McAb, which bound to the surface of adult worms, supplemented with complement. Since these effective McAb recognized the common epitope distributed in the parenchyma and surface of adults, it was suggested that adult worms, in place of schistosomula, would be used as the source of material for obtaining antigens to induce the protective immunity.