紫外线减毒日本血吸虫尾蚴免疫小鼠的皮肤组织细胞反应

CELLULAR IMMUNE REACTIONSIN THE SKIN OF MICE VACCINATED WITH UV-ATTENUATED CERCARIAE OF SCHISTOSOMA JAPONICUM

目的 :探讨紫外线减毒血吸虫尾蚴免疫宿主的皮肤组织在抗攻击感染中的作用。方法 :88只小鼠分为 4组 ,1、2组分别以 50± 3条紫外线减毒日本血吸虫尾蚴免疫或日本血吸虫尾蚴感染 ,5wk后以 10 0 0± 10 0条尾蚴进行攻击感染 ;3、4组分别以减毒尾蚴或尾蚴 10 0 0± 10 0条免疫或初次感染。各组均于感染或接种后 6- 12 0 h定时取局部皮肤组织作病理观察。结果 :( 1)免疫攻击组皮肤组织内炎症细胞杀伤童虫现象最明显、炎症反应最强且持续时间最长 ,嗜酸性粒细胞( EOS)浸润百分数最高 ;( 2 )感染攻击组呈现相似炎症反应但程度略轻 ;( 3)免疫对照组减毒童虫在皮肤内滞留时间延长 ,至 12 0 h皮下仍可见较多童虫 ;( 4 )感染对照组皮肤内的童虫数于 72 h后明显减少 ,童虫周围轻微炎症反应。电镜观察可见免疫攻击组童虫内部结构破坏 ,虫体周围 EOS、淋巴细胞增多 ,肥大细胞颗粒溶解。结论 :提示皮肤组织的细胞免疫反应在血吸虫减毒尾蚴免疫的宿主抗攻击感染保护性免疫中起重要作用。

AIM:To explore the role of the skin tissue from the hostimmunized with UV- attenuat- ed schistosome cercariae against the challenge infection.METHODS:Eighty- eight mice were divided into four groups.Group1 mice were challenged with1 0 0 0± 1 0 0 cercariae5 wk after immunizing with 5 0± 3ultraviolet(UV) - attenuated cercariae of Schistosoma japonicum. Group2 mice were challenged with1 0 0 0± 1 0 0 cercariae5 wk after infecting with5 0± 3cer- cariae.Group 3mice were immunized alone with 1 0 0 0± 1 0 0 cercariae.L ocal skin samples from mice of each group were taken at some certain time points from6 - 1 2 0 h after infection or immunization for pathological observation.RESULTS:In Group 1 ,the cellular reactions against schistosomula in skin tissue were the most evident and persistant,in which the per- cent of eosinophils(EOS) was also the highest.Similar reactions were observed in Group2 but not so intense as in Group 1 .A large number of attenuated schistosomula prolonging their persistence in the subcutanous tissue until1 2 0 h were observed in Group3,but the number of schistosomula in the skin of Group 4mice reduced evidently from 72 h,with slight cellular response.Ultrastructure studies revealed that most schistosomula in Group1 were completely disintegrated around which were numerous EOS,lymphocytes and occasion- al degranulated mast cells.CONCLUSION:Cellular immune response in the skin of the mice immunized with UV- attenuated cercariae might play an important role in the protective im- munity against challenge infection.