弓形虫主要表膜抗原SAG2 DNA疫苗的免疫保护作用研究  

STUDY ON THE PROTECTIVE IMMUNITY RESPONSES INDUCED BY THE RECOMBINANT PLASMID WITH THE SAG2 GENE OF TOXOPLASMA GONDII IN MICE

作　　者：龙彩虹 吴少庭[2] 翁亚彪[3] 高世同[2] 张仁利[2] 黄达娜[2] 

机构地区：[1]深圳市动物防疫监督所 [2]深圳市卫生防疫站分子生物室,广东深圳518020 [3]华南农业大学兽医学院

出　　处：《中国寄生虫病防治杂志》2005年第6期430-432,共3页Chinese Journal of Parasitic Disease Control

摘　　要：目的观察弓形虫pVAX1-SAG2真核重组质粒的免疫保护作用,为弓形虫病的免疫预防提供理论及实验依据。方法大量制备重组质粒,免疫小鼠,3周后同量加强免疫1次,5周后无菌取小鼠脾脏,制备脾细胞,用MTT法测定淋巴细胞转化率;用免疫荧光法测定CD4+、CD8+细胞。用弓形虫RH株速殖子经皮下注射攻击感染,每只鼠接种0.1 ml(约含1000个虫体),观察小鼠存活情况。结果对小鼠的脾脏T淋巴细胞亚群CD4+、CD8+进行分析,与对照组比较,免疫组小鼠CD4+细胞显著增多(P<0.05);而CD8+细胞数各组之间差异无显著性(P>0.05);淋巴细胞转化率各组间差异无显著性(P>0.05);攻击感染后,pVAX1-SAG2免疫组小鼠平均存活(7.8±1.8)d,与对照组比较显著延长(P<0.05)。结论弓形虫pVAX1-SAG2真核重组质粒能在组织内表达,并诱导小鼠产生细胞免疫反应。Objective To observe the immune responses of constructed recombinant plasmid, pVAXl, containing SAG2 gene from Toxoplasma gondii and its protective effect against T. gondii in mice. Methods BALB/c mice were inoculated plasmid DNA by intramuscular injection. 5 week after the booster injection, spleens were taken from mice, and the splenocytes were isolated and counted. The proliferation activity of T lympheytes of those splenoeytes was detected by MTT assay. And the number of CD4^＋/ CD8^＋ T cells were counted using direct immuno-fluoreseent assay. The experimental mice were challenged by tachyzoits of RH isolate of T. gondii via subcutaneous injection 5 weeks after immunization, The proliferative responses of control and immunized mouse spleen cells were generated when stimulated by ConA. Results The number of CD4^＋ T cells in the immunized group was significantly increased compared with that of the control ones （P〈0.05）, whereas the number of CD8^＋ T cells was higher than that of the control groups, but not significently （P〉0.05）. All experimental mice were dead 4-9 days after being challenged with virulent RH strain of T. gondii isolate, with the exception of two mice in the pVAX1 SAG2 group. The survival time of mice in the immunized group was obviously prolonged（P〈0.05） than that of the control groups. Conclusion The present study explored noval way of DNA vaccination against T. gondii infection. The findings have important implications for potential immunological prevention and control of T. gondii infections in both humans and animals.

关 键 词：弓形虫 DNA疫苗 细胞免疫应答 

分 类 号：R382.5[医药卫生—医学寄生虫学]