pVAX1/SjTSP2 DNA疫苗免疫预防小鼠日本血吸虫病的效果评估

PROTECTIVE EFFICACY OF PVAX1/SJTSP2 AS A DNA VACCINE AGAINST SCHISTOSOMIASIS JAPONICUM IN BALB/C MICE

为评估SjTSP2分子作为日本血吸虫DNA疫苗候选抗原分子的潜力,本实验扩增了编码该分子的DNA片段,构建了重组真核质粒pVAX1/SjTSP2,检测其在哺乳动物细胞中表达情况后,通过基因枪轰击法免疫小鼠,应用ELISA、流式细胞术等检测重组质粒诱导的免疫反应,计算减虫减卵率,评估对小鼠日本血吸虫病的免疫保护效果。间接免疫荧光试验结果显示该质粒能在293T细胞中表达。质粒免疫小鼠诱导了显著升高的特异性IgG抗体和IFN-γ、IL-4等细胞因子。小鼠免疫保护试验结果表明,免疫组小鼠虫荷数较PBS对照组增加12.4%(P=0.368),但肝组织虫卵减少10.01%(P=0.486)。说明制备的DNA疫苗能刺激小鼠产生较强的免疫反应,但诱导的免疫保护作用并不理想,为血吸虫DNA疫苗研究提供了参考数据。

To evaluate the protective efficacy of pVAX1/SjTSP2 as a DNA vaccine against Schistosomiasis japonicum,a recombinant plasmid pVAX1/SjTSP2 was constructed,and expressed in 293T cells.Purified plasmid was delivered into the mice by particle bombardment with a dose of 2.5μg/mouse.Specific anti-SjTSP2 antibody level were significantly increased in all animals vaccinated with pVAX1/SjTSP2 detected by ELISA in comparison to PBS control group.Splenocytes from mice vaccinated with pVAX1/SjTSP2 produced considerably higher levels of T helper 1 response–enhancing cytokines（IFN-γ） and T helper 2（Th2） response–enhancing cytokines（IL-4） by flow cytometry.The worm burden of vaccinated mice was increased 12.04%（P=0.368）,and liver egg count reduced 10.01%（P=0.486）,compared with PBS control group,respectively.This result may provide another evidence for evaluating SjTSP2 potential as a vaccine candidate.