【摘要】 目的　探讨干扰素 γ重组质粒对日本血吸虫组织蛋白酶B核酸疫苗在小鼠抗血吸虫作用的影响。　方法　将小鼠干扰素 γ基因PCR扩增片段克隆入真核表达载体pCDNA3 1以构建重组真核表达质粒pCDNA3 1 IFN γ ,并与日本血吸虫组织蛋白酶B真核表达质粒VR10 12 Sj3 1一同免疫小鼠。小鼠分为 4组 ,其中实验组每鼠同时肌注VR10 12 Sj3 1及pCDNA3 1 IFN γ各 10 0 μg ,3个对照组分别为VR10 12 Sj3 1肌注 10 0 μg ,pCDNA3 1 IFN γ肌注 10 0 μg和载体VR10 12及pCHAN3 1肌注各 10 0 μg。共免疫 3次 ,每次间隔 2周。于末次免疫后两周免疫组化检测表达质粒在小鼠肌细胞的表达 ,于末次免疫后 3周经小鼠皮肤攻击感染 40± 1条日本血吸虫尾蚴。 45d后杀小鼠计算减虫率。　结果　VR10 12 Sj3 1及pCDNA3 1 IFN γ均在小鼠肌细胞表达 ,日本血吸虫Sj3 1核酸疫苗联合IFN γ重组质粒免疫可诱导小鼠产生 2 7 3 7%的减虫率 ,与日本血吸虫Sj3 1核酸疫苗单独免疫组比较减虫率显著 (P <0 0 5 )。　结论　IFN γ表达质粒能增强日本血吸虫组织蛋白酸B核酸疫苗的抗日本血吸虫的作用更多还原

【Abstract】 Objective To explore the effect of recombinant plasmid encoding IFN-γ on the action of cathepsin B DNA vaccine against Schistosoma japonicum (Sj) in mice. Methods PCR amplified DNA fragment of murine IFN-γ was cloned into eukaryotic expression vector pCDNA3.1 to construct recombinant expression plasmid pCDNA3.1-IFN-γ that was used to immunize mice with cathepsin B DNA vaccine VR1012-Sj31.Mice divided into 4 groups were intramuscularly injected 100μg of each VR1012-Sj31 and pCDNA3.1-IFN-γ for the test group,while for the 3 control groups mice were injected respectively the same dosage of VR1012-Sj31 alone,pCDNA3.1-IFN-γ alone and each of the 2 vectors.All mice were immunized 3 times with 2 weeks interval.The expression of the target gene in the quadriceps femoris was determined with Immunohistochemistry at 2 weeks after the last immunization,while mice were percutaneously challenged with 40±1 Schistosoma japonicun cercariae 3 weeks after the last immunization.All the mice were sacrificed 45 days later and the worms recovered were counted. Results Both VR1012-Sj31 and pCDNA3.1-IFN-γ were expressed in muscular cells of the immunized mice.Co-immunization of cathepsin B DNA vaccine with plasmid encoding mIFN-γ elicited 27.37% of worm reduction rate,showing significant difference (P<0.05) as compared with that of cathepsin B DNA vaccine control. Conclusion Partial protecive immunity against Schistosoma japonicum induced by cathepsin B DNA vaccine of Schistosoma japonicum can be enhanced by co-immunization with plasimid encoding IFN-γ.更多还原