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目的观察日本血吸虫组织蛋白酶B DNA疫苗与IL-4真核表达质粒联合免疫小鼠的效果. 方法将小鼠IL-4 基因PCR扩增片段克隆入真核表达载体pcDNA3以构建重组表达质粒.小鼠分为4组, 每组12只,实验组(A)每鼠肌注组织蛋白酶B DNA疫苗和IL-4表达质粒各100 μg,同时设立组织蛋白酶B DNA疫苗对照组(B)、IL-4表达质粒对照组(C)和空载体对照组(D),共免疫3次.2周后用免疫组化检测表达质粒在小鼠肌细胞的表达,3周后经皮肤攻击感染小鼠40±1条日本血吸虫尾蚴.计算减虫和减卵率,观察免疫保护性. 结果重组IL-4质粒和组织蛋白酶B DNA疫苗均在小鼠肌细胞表达.用重组IL-4质粒和组织蛋白酶B DNA疫苗联合免疫诱导小鼠产生43.20% 的减虫率和76.63% 的减卵率,与组织蛋白酶B DNA疫苗单独免疫比较差异均有显著性(P<0.001,P<0.05). 结论联合IL-4表达质粒免疫可能提高日本血吸虫组织蛋白酶B DNA疫苗的抗血吸虫保护性免疫.“,”Objective To examine the efficacy of co-immunization of cathepsin B DNA vaccine of Schistosoma japonicum(Sj) with plasmid encoding IL-4 in mice. Methods The recombinant plasmid was constructed by cloning PCR amplified murine IL-4 gene into eukaryotic expression vector pcDNA. Mice were divided into 4 groups. The test group was intramuscularly injected 100 μg per mouse of each cathepsin B DNA vaccine and plasmid encoding IL-4 while 3 control groups injected with cathepsin B DNA vaccine alone, plasmid encoding IL-4 and vector respectively were set up at the same time. Three times of immunization of mice were followed by determination of muscular cell expression of the interests with immunohistochemistry 2 weeks later and percutaneously challenging mice with 40±1 Sj cercariae 3 weeks later. Immune protection was assessed by worm and egg reduction rates. Results The recombinant mIL-4 plasmid and cathepsin B DNA vaccine were expressed in muscular cells of the immunized mice. Co-immunization of cathepsin B DNA vaccine with plasmid encoding mIL-4 elicited 43.20% of worm reduction rate and 76.63% of egg reduction rate, showing significant difference(P<0.001, P<0.05 respectively) compared with immunization of cathepsin B DNA vaccine alone. Conclusion The protective immunity against S. japonicum induced by cathepsin B DNA vaccine might be improved by co-immunization with plasmid encoding IL-4.