弓形体重组质粒pcDNA_3-SAG1免疫小鼠诱导的细胞免疫应答研究

目的 :用 pc DNA3- SAG1真核表达质粒直接免疫小鼠 ,观察 DNA免疫所诱导的小鼠细胞免疫应答 ,为研制弓形虫疫苗奠定基础。方法 :大量制备重组质粒 pc DAN3- SAG1,然后将其导入 BAL B/ c小鼠体内 ,每隔 2 1d接种一次 ,一共免疫三次。用 MTT方法对脾脏的 NK细胞和其淋巴细胞的转化率进行测定 ;采用免疫荧光法对 CD4+、CD8+ 细胞进行测定。结果 :实验组 NK细胞杀伤率为 :70 .0± 3.6 4,而 pc DNA3及空白对照分别为 :48.5± 6 .0 8和 47.0± 5 .93。实验组 NK细胞活性比对照组明显增高 (P<0 .0 5 ) ,而 pc DNA3质粒及空白对照组差异无显著性 (P>0 .0 5 ) ;对 T淋巴细胞亚群 CD4+、CD8+进行动态分析 ,可见随着感染时间的延长 ,CD8+的数量逐渐上升 ,CD4+ / CD8+的比率逐渐下降 ,实验组与 pc DNA3质粒及空白对照有明显差异 (P<0 .0 5 ) ;Con A刺激小鼠淋巴细胞转化实验 ,能刺激免疫鼠及对照鼠淋巴细胞增生 ,实验组与 pc DNA3质粒及空白对照组差异无显著性 (P>0 .0 5 )。结论 :重组质粒pc DNA3- SAG1免疫 BAL B/ c小鼠可诱导一定的细胞免疫。

Study on the cellular immune responses induced by DNA veccine with the SAG1 gene of Toxoplasma gondii in mice

Objective:Directly immunize mice with the recombinant plasmid pcDNA 3-SAG1,to observe and test the cellular immune responses induced by pcDNA 3-SAG1,and to lay a foundation of further study on the vaccine development of Toxoplasma gondii.Methods:Large scale prepared rceombinant plasmid pcDAN 3-SAG1 was injected into the BABL/c mice by muscles.Two booster injections were given at 3rd week and 6th week followed the first injection.The killing activity of NK cells and transform rate of spleen was tested by MTT,and T cell subgroup CD4 + were tested by the indirect immune fluorescent assay.Result:The killing rate of the NK cells from immunized mice was (70±3.64),and that of control group was (48.50±6.08 and 47±5.93);The activity of immunized mice NK cell was remarkable higher than that of control ( P <0.05);the kinetic analysis of CD4 +、CD8 + T cell subgroup,showed that the number of CD8 + gradually increased and the rate of CD4 +/CD8 + gradually reduced with time prolong,there were remarkable different between control mice and immunized ones ( P <0.05);the proliferative responses of control and immunized mouse spleen cells were generated when stimulated by ConA,but there is no remarkable diference between control mice and immunized ones ( P <0.05).Conclusion:pcDNA 3-SAG1 vaccine could elicit BALB/c mice to generate cellular immune responses.