弓形虫SAG1,ROP1基因及其复合抗原基因的核酸免疫研究

Immune Responses in Mice Vaccinated with Recombinant Plasmid pcDNA3 Containing SAG1 and ROP1 Gene from Toxoplasma gondii

目的检测混合SAG1和ROP1编码基因真核表达质粒疫苗诱导小鼠的免疫应答，评价其抗弓形虫感染的保护性免疫效果．方法 将SAG1和编码基因片段克隆入pEGFP-N3表达载体，构建重组质粒；RT-PCR体外验证重组质粒在NH3T3细胞中的表达；通过检测抗体、抗体分型及细胞因子来评价体液免疫和细胞免疫：腹腔内注射毒性株弓形虫速殖子攻击免疫小鼠．结果 RT-PCR结果显示重组质粒能在哺乳动物细胞内表达；SAG1和ROP1混合重组质粒疫苗诱导小鼠产生很强的体液免疫和细胞免疫，对于毒性株弓形虫感染攻击具有保护作用．结论 不同候选抗原编码基因重组质粒能够诱导小鼠产生抗弓形虫感染保护性免疫，提示含有多种成分的混合DNA疫苗的研制可作为核酸免疫研究的策略之一．

Objective To examine the immune response elicited by SAG1 and ROP1 encoding plasmids and assess the protective effect of the DNA vaccination against toxoplasmosis. Methods DNA fragments encoding SAG1 and ROP1 were cloned into pEGFP-N3 expression vector to construct serial recombinant plasmids. In the NIH3T3 cells were verified by RT-PCR. Humoral and cellular responses were assayed by using ELISA for detection of Ab, Ab isotype and cytokines. All mice were challenged with highly virulent tachyzoites via intraperitoneal injection. Results RT-PCR indicated that the SAGI and ROPI could be expressed in the expression recombinmant plasmid transfected NIH3T3 cell line. Mice genetically immunized with the recombinant plasmids elicited strong humoral and cellular immune responses and showed partial protective effect to mice challenged with highly virulent isolate to Toxoplasma gondii. Conclusions A strategy of vaccination with recombinant plasmids encoding different antigens might be useful to offer protection against toxoplasma and this could have an implication in the design of future multicomponent DNA vaccines.