刚地弓形虫ROP2-P30复合重组蛋白疫苗对BALB／c小鼠免疫保护性的研究

目的用刚地弓形虫ROP2-P30复合重组蛋白疫苗免疫BALB/c小鼠观察对机体的影响,为研制安全有效的弓形虫疫苗奠定基础。方法PCR方法从刚地弓形虫基因组中扩增出ROP2和P30片段,将这两个片段分别亚克隆至pET-30a原核表达载体中,表达出ROP2-P30复合重组蛋白。用蛋白疫苗免疫BALB/c小鼠,ELISA检测免疫小鼠后体液中抗体和细胞因子的变化,观察攻击试验小鼠的的死亡率。结果ROP2-P30复合重组蛋白疫苗免疫BALB/c小鼠诱导机体产生大量的IgM、IgG抗体和IFN-γ、IL-2及IL-4细胞因子。攻击试验表明,复合重组蛋白免疫组和对照组相比,小鼠的存活时间明显延长。结论ROP2-P30复合重组蛋白免疫BALB/c小鼠诱导其产生高水平的体液和细胞免疫应答,该复合重组蛋白是抗刚地弓形虫感染的候选疫苗之一。

PROTECTIVE EFFECT OF MULTIPLE RECOMBINANT ANTIGENSAGAINST TOXOPLASMOSIS IN MICE

Objective To observe the effect of multiple recombinant antigen vaccine on BALB/c mice in order to lay foundation for developing an effective and safe protein vaccine against Toxoplasma gondii. Methods The genes encoding ROP2 and P30 were amplified from T. gondii genome by PCR. Two genes fragments were subcloned into the expression vector, respectively. The multiple recombinant antigen (ROP2-P30) of T. gondii was expressed in vitro. The immune response of host to the antigen was investigated by detection of specific antibodies reaction to ROP2-P30 recombinant protein and production of cytokines. Mice were immunized with multiple recombinant protein and challenged with lethal strain of T. gondii RH. Results BALB/c mice intramuscularly immunized with multiple recombinant protein induced specific high titer of IgM and IgG antibodies as well as IFN-γ, IL-2 and IL-4 cytokines in mice. In contrast, IgA was detected in low titer, whereas no IL-12 and IL-6 were detected. Moreover, the multiple recombinant protein induced mice to produce a long-lasting protection against a lethal challenge with the highly virulent T. gondii RH strain compared to the control group. Conclusion The immune protection induced by ROP2-P30 recombinant protein against T.gondii may be regulated by both hormone- and cell-mediated immune response. ROP2-P30 recombinant protein may be an excellent vaccine candidate against T. gondii.