细粒棘球绦虫Eg95基因疫苗和重组抗原诱导小鼠免疫应答的比较研究

目的观察比较细粒棘球绦虫Eg95重组抗原和基因疫苗诱导小鼠的免疫应答状况。方法实验组和对照组小鼠分别注射Eg95重组抗原(rEg95)、费氏佐剂(FCA)、pcDNA3-Eg95基因疫苗、pcDNA3质粒和生理盐水,收集各组血清用酶联免疫吸附(ELISA法)检测抗体IgG和IgG2a亚类水平;采集脾细胞用四甲基偶氮唑盐试验(MTT法)检测免疫小鼠的脾淋巴细胞增殖反应。结果rEg95免疫组小鼠在第二次免疫后开始检测到抗Eg95抗原的IgG,并随着免疫次数的增多,血清抗体效价升高,在第1次免疫后第10周时,免疫抗体滴度可达到1∶25,600。Eg95基因疫苗免疫的小鼠产生抗体滴度随免疫次数的增加而升高,最高可达1∶3,200,但是低于Eg95重组蛋白免疫小鼠产生的抗体滴度水平。pcDNA3-Eg95免疫组产生IgG2a亚类抗体水平明显高于对照组和rEg95组。在第四次免疫后,进行淋巴细胞转化试验,MTT法检测证实rEg95和pcD-NA3-Eg95免疫的小鼠,其脾细胞均可在体外被特异性刺激增生。结论细粒棘球绦虫Eg95重组抗原和基因疫苗均可诱发小鼠产生特异性免疫应答。

Comparison on the immune responses induced by the EG95 hydatid vaccine and the recombinant EG95 antigen in mice

To investigate the immunological effects induced by the EG95 hydatid vaccine and the recombinant EG95 antigen in mice, BALB/c mice were immunized with recombinant EG95 antigen, DNA vaccine pcDNA3-EG95, Freund'complete adjuvant(FCA), plasmid pcDNA3 and normal saline (NS) respectively. The level of anti-Eg95 IgG and IgG2a in murine serum was determined by ELISA and the proliferative activity of the splenic lymphocytes was tested by MTT assay. Results of this study showed that the specific IgG response was induced during the second week after immunization and continued to increase until the 10 th week. The highest titer of specific antibodies increased was 1:25,600 in sera of mice immunized with the recombinant EG95 antigen. There was a significant difference in the IgG levels between the mice immunized with the recombinant EG95 antigen and FCA control as well as between groups of mice immunized with plasmid pcDNA3-EG95 and plasmid pcDNA. In addition, the specific antibody titer in mice immunized with DNA vaccine pcDNA3-EG95 was 1:3200, and appeared to be lower than that in mice immunized with the rcombinant EG95 antigen. However, The level of IgG2a antibodies was higher in mice immunized with plasmid pcDNA3-EG95 than those of recombinant EG95 antigen immunized group and the control group. As demonstrated by the MTT assay, the recombinant EG95 antigen could stimulate specifically the proliferation of splenic T lymphocytes in mice immunized DNA vaccine pcDNA3-EG95 or recombinant EG95 antigen. It is concluded that both DNA vaccine pcDNA3-EG95 and recombinant EG95 antigencan induce the specific cell-mdiated and humoral immunity of mice immunized with these preparations.