日本血吸虫重组跨膜蛋白4免疫保护性的研究

The study of recombinant tetraspanin-4 (rSj-Ts4) in immuno-protection of Schistosoma japonicum

目的寻找新的血吸虫疫苗候选分子,观察日本血吸虫重组跨膜蛋白4(rSj-Ts4)在小鼠抗血吸虫感染中的免疫保护作用。方法以rSj-Ts4每鼠50μg/100μ1、100μg/100μ1和200μg/100μl分别免疫BALB/c小鼠,同时设生理盐水对照组,用日本血吸虫尾蚴攻击模型小鼠,计算减虫率、减卵率,观察它们的抗血吸虫感染作用;病例切片观察肝脏组织中肉芽肿的变化。结果用重组Sj-Ts4免疫BALB/c小鼠,第1、第2和第3组诱导的减虫率分别为22.6%、27.1%和30.8%,经t检验各实验组与对照组间差异均无显著性意义(P<0.05)。第1、第2和第3组诱导的肝组织减卵率分别为31.2%、34.29%和35.2%,经t检验各实验组与对照组间差异均无显著性意义(P<0.05)。病理可见重组Sj-Ts4组小鼠肝脏表面较光滑,质地较软,色泽略带暗红色,隐约可见少量灰白色小点,虫卵结节较少;生理盐水组小鼠肝组织中可见大量的虫卵肉芽肿形成,肉芽肿体积较大,周围有大量炎细胞浸润,较多的肝细胞变性坏死。结论结果表明日本血吸虫重组跨膜蛋白4(rSj-Ts4)可能是一种潜在的血吸虫病疫苗候选分子。

Objective To probe a new vaccine candidate of Schistosoma japonicum,and observe the recombinant tetraspanin-4 protein(Sj- Ts4) for the immuno-protection effect on mice attacked with cercariae.Methods The BALB/c mice were immunized with the recombinant Sj-Ts4 by the dosage of 50μg/100μl,100μg/100μl and 200μg/100μl,respectively,followed by challenging infection and the immuno-protection was evaluated.Meanwhile,the liver was removed.Some of them were digested and counted for the egg reduction rate.HE staining method was used to detect the hepatic changes and granuloma.Results The molecular vaccine was injected into BALB/c mice.The immuno-protective effect showed that the worm reduction was 22.6%,27.1%,30.8%in group 1,2 and 3,respectively,and there were no remarkable significance between the groups(P<0.05).The number of eggs in liver tissue was reduced by 31.2%,34.29%,and 35.2%,respectively,also there were no remarkable significance between the groups(P<0.05).Gross observation showed that the livers in control group were dark brown and hard,with massive nodules of worm eggs diffused in the livers.The recombinant Sj-Ts4 group has some extent of amelioration,the hepatic histological section demonstrated that there are generous big granulomas containing eggs in the livers of control group,with extensive infiltration of inflammatory cells,degeneration and necrosis of hepatic cells.The recombinant Sj-Ts4 vaccine group reversed the hepatic injury better than the control group.The inflammatory reaction around the eggs granulomas was light.Conclusion The molecular vaccine of rSj-Ts4 had some protection effect on mice and might be used as a latent vaccine candidate.