日本血吸虫SjC23蛋白质疫苗对核酸疫苗免疫增强作用的研究

BOOSTING WITH PROTEIN VACCINE TO ENHANCE THE PROTECTIVE IMMUNITY OF SjC23 DNA VACCINE

目的 研究 Sj C2 3蛋白质疫苗对 Sj C2 3DNA疫苗增强小鼠的免疫保护作用的效果。方法 分别构建和制备 Sj C2 3DNA疫苗 (pc DNA3.1- Sj C2 3)和 Sj C2 3大亲水片段融合蛋白质 (GST-HD)疫苗。把 48只 BAL B/ c小鼠随机分为 A、B、C、D 4组 ,每组 12只。 A组 (DNA和蛋白质疫苗联合免疫组 )每只小鼠分别在第 0、2周经股四头肌注射 10 0μg Sj C2 3质粒 DNA,在第 4周经背部皮下多点注射 5 0 μg GST- HD+5 0 μg CFA;B组 (Sj C2 3DNA组 )每只小鼠分别在第 0、2、4周经股四头肌注射 10 0 μg Sj C2 3质粒 DNA;C组 (蛋白质疫苗组 )于第 4周每鼠经背部皮下多点注射 5 0 μgGST- HD+5 0 μg CFA1次 ;D组 (对照组 )每鼠分别在第 0、2、4周肌注 10 0 μg pc DNA3.1。各组在末次免疫后 4周每鼠以 45± 2条日本血吸虫尾蚴攻击感染 ,攻击后 45 d剖杀小鼠 ,计数成虫及肝内虫卵数。在免疫前、末次免疫后和攻击后从小鼠尾静脉采血 ,分离血清 ,用 Western- blot法检测抗体反应。结果 联合组与质粒对照组相比 ,获得了 42 .9%的减虫率和 6 0 .0 %的减卵率 ,均显著高于单独Sj C2 3DNA疫苗组 2 8.1%的减虫率和 37.9%的减卵率 ,及单独蛋白质疫苗组 (GST- HD) 2 3.8%减虫率和 39.5 %的减卵率 (P均 <0 .0 5 )。联合组抗体水平?

Objective To investigate the protective immunity efficacy of SjC23 DNA vaccine enhanced by SjC23 protein vaccine in Schistosoma japonicum infected mice.Methods Forty eight of female BLAB/c 5-6 weeks old mice were divided into A?B?C and D groups,12 mice of each group. In group A (SjC23 DNA+GST-HD co-immunized group), each mouse was immunized with 100 μg pcDNA3.1-SjC23 plasmid DNA by intramuscule (i.m.) for two times at week 0,2, and at week 4 was immunized with 50 μg GST-HD+50 μg CFA by subcutaneous; In group B (SjC23 DNA group), each mouse was immunized (i.m.) with 100 μg pcDNA3.1-SjC23 plasmid DNA for three times; In group C(SjC23 protein group), each mouse was immunized with 50 μg GST-HD+50μg CFA by subcutaneous at week 4; In group D(control group),each mouse was immunized (i.m.) with 100 μg pcDNA3.1 plasmid DNA for three times at week 0,2,4. Thirty days after last immunization each mouse was challenged with 45±2 cercariae of Schistosoma japonicum Chinese strain. At day 45 after challenge, all mice were sacrificed and perfused, the numbers of recovered worms and hepatic eggs were counted. Before immunization,after the last immunization and after challenge,the anti-SjC23 antibodies were detected with Western-blot method. Results In the co-immunized group(A), the worm reduction rate and the egg reduction rate were 42.9% and 60.0% compared with that in control group(D) respectively, they were significantly higher than that in SjC23 DNA group (B) (28.1% of worm reduction rate and 37.9% of egg reduction rate) (P<0.05) and in protein group(C) (23.8% of worm reduction rate and 39.5% of egg reduction rate) (P<0.05). After the last immunization, the antibody response of the co-immunized group(A) were higher than that in SjC23 DNA group(B). Conclusion SjC23 protein vaccine could enhance the protective immunity efficacy of SjC23 DNA vaccine against Schistosoma japonicum in infected BALB/c mice.