日本血吸虫中国大陆株TPI DNA疫苗诱导BALB/c小鼠保护性免疫力的研究

PROTECTIVE IMMUNITY OF DNA VACCINE ENCODING SCHISTOSOMA JAPONICUM CHINESE STRAIN TRIOSE-PHOSPHATE ISOMERASE IN INFECTED BALB/c MICE

目的 研究日本血吸虫中国大陆株磷酸丙糖异构酶 (Sj CTPI) DNA疫苗诱导 BAL B/ c小鼠的保护性免疫作用。方法 将 39只 BAL B/ c小鼠随机分成 3组 :A组 (对照组 ) ,肌注 pc DNA3.1质粒 DNA10 0 μg/鼠 ;B组 (实验组 ) ,每鼠肌注 pc DNA3.1- Sj CTPI10 0 μg;C组 (加强组 ) ,每鼠肌注 pc DNA3.1- Sj CTPI10 0 μg及 pc DNA3.1- P35和 pc DNA3.1-P40的混合物 10 0 μg。每两周免疫 1次 ,共计 3次。末次免疫 4周后 ,每鼠用 45条尾蚴进行攻击 ,45 d后剖杀小鼠 ,计数成虫以及每鼠肝组织内虫卵数 ;于攻击前每组各取两只小鼠采用 51 Cr释放法测定 Sj CTPI介导的特异性细胞毒作用 ;EL ISA检测攻击前后的抗 TPI的抗体水平。 结果 用 EL ISA检测抗 TPI抗体的结果表明 ,攻击前 A组的 10份血清均为阴性 ,B组 5 / 10份血清出现弱阳性 ,C组也有 6 / 10份血清出现弱阳性反应。51 Cr释放法测定细胞毒活性结果表明 ,A、B、C组细胞毒活性分别为 9.1%、2 7.6 %和 5 4.4%。与对照组相比 ,实验组的减虫率、减卵率分别为 30 .2 %、5 2 .9% ;加强组的减虫率、减卵率分别为 32 .7%、47.0 %。 结论 进一步证实了 Sj CTPI DNA疫苗作为抗血吸虫病核酸疫苗的潜力。

Objective To develop SjCTPI DNA vaccine for schistosomiasis japonica, and test the immune responses and the protective efficacy after immunization and challenge in BALB/c mice. Methods 39 of BALB/c mice were devided into three groups, group A (control group), each mice was injected with 100 μg of pcDNA3.1 by intramuscle, group B (experimental group) was injected with 100 μg of pcDNA3.1-SjCTPI, group C (strengthen group) was injected with 100 μg of pcDNA3.1-SjCTPI and 100 μg of mixture of pcDNA3.1-P35 and pcDNA3.1-P40. Eath mice was immunized three times at a two-week interval and challenged with 45 cercariae of Schistosoma japonicum Chinese strain four weeks post-immunization. Then the mice were sacrificed and perfused at 45 days after challenge, the numbers of recovered worms and hepatic eggs were counted. Cytotoxic activity mediated by SjCTPI was detected with the 51 Cr release assay. ELISA were performed for detection of anti-rTPI antibodies. Results The anti-rTPI antibody detection with ELISA showed that ten sera samples from the control group were negative, five of ten serum samples from group B were weak positive, six of ten from group C were weak positive too. The cytotoxic activity of the control group was 9.1%, while the cytotoxic activities of group B and group C were 27.6% and 54.4% respectively. The worm and egg reduction rates of group B and group C were 30.2 %, 52.9% and 32.7%, 47.0% respectively in comparison with the control group. Conclusion The results further proved the possibility of SjCTPI DNA vaccine as a potential DNA vaccine of schistosomiasis.