日本血吸虫组织蛋白酶B DNA疫苗不同免疫途径免疫保护效果研究

STUDY ON PROTECTIVE IMMUNITY OF CATHEPSIN B DNA VACCINE AGAINST SCHISTOSOMA JAPONICUM IN DIFFERENT IMMUNIZATION ROUTES

目的 :观察本室所构建日本血吸虫大陆株 31kDa组织蛋白BDNA疫苗在BALB/c小鼠体内的不同免疫途径的免疫保护效果。方法 :用纯化的空白质粒载体VR1 0 1 2、重组质粒VR1 0 1 2 Sj31免疫BALB/c鼠 ,将 36只 6～ 8周龄BALB/c鼠随机分为 3组 ,每组 1 2只 ,对照组 (A组 )肌肉注射空白质粒载体VR1 0 1 2 ,实验组 (B组 )皮下注射重组质粒VR1 0 1 2 Sj31 ,C组肌肉注射重组质粒VR1 0 1 2 Sj31。质粒剂量均为 1 0 0 μg ,每隔 2w免疫 1次 ,共免疫 3次 ,第 3次免疫后第 2 1d ,每只鼠经腹部感染 1 0条尾蚴 ,4 2d后剖杀计数各小鼠成虫数和每克肝卵数 ,观察诱导产生的减虫和减卵效果 ,并用ELISA分析小鼠血清中的抗体。结果 :ELISA分析表明 ,第 3次免疫后小鼠出现特异性IgG抗体。与空白质粒对照组比较 ,2个实验组的减虫率分别为 1 5 .0 % (P >0 .0 5 )和 2 5 .0 % (P <0 .0 5 ) ,减卵率分别为 38.2 2 %和 5 4.90 % (P <0 .0 0 1 )。与皮下免疫组相比 ,VR1 0 1 2 /Sj31肌肉免疫组的减卵率分别为 2 6 .99% (P <0 .0 0 1 )。结论 :DNA疫苗VR1 0 1 2 Sj31能诱导小鼠产生一定水平的抗日本血吸虫感染保护作用 ,肌肉注射的保护效果大于皮下注射。

Objective:To observe the protective immunity induced by the DNA vaccines of VR1012-Sj31 of Schistosoma japonicum(Sj) in BALB/c mice in different way.Methods:Thirty six BALB/c mice were divided into three groups.Of control group A,each mouse was injected at quadriceps femoris with 100μg VR1012 plasmid DNA;of group B,each mouse was injected subcutaneously with 100μg VR1012-Sj31 plasmid DNA;of group C,each mouse was injected intramuscularly with 100μg VR1012-Sj31 plasmid DNA.All mice were immunized three times with an interval of 2 weeks and were challenged each with 10 cercariae of Sj at the 21th days after final immunization.At day 42 after challenge,all mice were sacrificed,the numbers of worms and hepatic eggs were counted.Antibody level in the sera of mice before and three weeks after immunization was determined with ELISA.Results:There are specific IgG in the serum of mice in the test groups after 3rd immunization.Compared with the control group,the worm reduction was 15.0%(P>0.05) and 25.0%(P<0.05);the egg reduction was 38.22% the eggreduction of C group was 26.99%(P<0.001).Conclusion:The DNA vaccines,VR1012-Sj31 could induce partial protective immunity against Sj in mice.The protective immunity by intramuscular injection was better than that by subcutaneous injection.