细胞因子表达质粒对恶性疟原虫顶端膜抗原1DNA免疫的调节作用

Modulation of Immune Response to Plasmodium falciparum Apical Membrane Antigen 1 DNA Vaccine by Cytokine Plasmids

目的 探讨细胞因子表达质粒对小鼠DNA免疫的促进和调节作用。 方法 构建编码恶性疟原虫顶端膜抗原 1(AMA1)完整胞外域的DNA免疫质粒VR10 2 0 /E ,构建编码小鼠细胞因子 (GM CSF)、白细胞介素 (IL)如IL 4和IL 12的真核表达质粒pcDNA3 /GM CSF、pcDNA3 .1( ) /IL 4和pIL 12以及双顺反子质粒pGM CSF/pTPA E ,分组免疫小鼠 ,ELISA检测血清中特异性IgG及其亚类的水平 ,取小鼠脾细胞进行体外增殖。 结果 3种细胞因子质粒均有效增强了小鼠针对VR10 2 0 /E的免疫应答 ,抗体水平增加 7至 10倍 ,其中pcDNA3 /GM CSF质粒和pIL 12质粒分别显著促进了小鼠的IgG1和IgG2a应答 ,小鼠脾细胞的体外增殖水平亦有明显提高。 结论 利用编码GM CSF、IL 4和IL 12的表达质粒作为佐剂可有效增强小鼠针对AMA1DNA的免疫应答 ,并对免疫应答的类型产生调节作用。

Objective To explore the effect of cytokine encoding plasmids on DNA immunization in mice. Methods Prototype DNA vaccine VR1020/E which contain Plasmodium falciparum apical membrane antigen 1 (AMA1) ectodomain was constructed, and eukaryotic expression vectors pcDNA3/GM-CSF, pcDNA3.1(-)/IL-4, pIL-12 and pGM-CSF/pTPA-E were also built. BALB/c mice were immunized with VR1020/E alone or with VR1020/E plus different cytokine plasmids. Serum IgG and its subtype were determined by ELISA and in vitro splenocyte proliferation assay was done. Results GM-CSF, IL-4 and IL-12 encoding plasmids all promoted mice immune response to VR1020/E, the antibody level increased 7 to 10 times and splenocyte proliferation was enhanced too. Plasmid pcDNA3/GM-CSF induced much more IgG1 whereas plasmid pIL-12 induced much more IgG2a. Conclusion Cytokine encoding plasmids might be used as adjuvant in AMA1 DNA immunization.