牛IL-18真核表达载体的构建及其对FMD疫苗的免疫增强作用

Construction of eukaryotic expression plasmids coding BoIL-18 and its immunoenhancement on Foot-and-Mouth Disease virus vaccine

【目的】探讨牛IL-18(BoIL-18)对口蹄疫(FMD)灭活疫苗的免疫增强作用。【方法】PCR扩增BoIL-18蛋白基因片段,将其定向克隆至pcDNA3.1载体中,构建牛IL-18真核表达质粒pcDNA3.1-BoIL18。将pcDNA3.1-BoIL18与FMD灭活疫苗联合免疫小白鼠,同时设空载体和单纯接种FMD灭活苗组为对照,通过对口蹄疫抗体效价的检测、T淋巴细胞转化试验及NK细胞活性检测试验,研究BoIL18对FMD灭活疫苗的免疫增强作用。【结果】同时接种FMD灭活疫苗和IL-18真核表达质粒的小白鼠T淋巴细胞转化率和NK细胞活性,从接种第21天开始均明显高于单纯FMD灭活苗接种组(P<0.05),所产生的中和抗体效价从第28天开始与单纯接种FMD灭活疫苗组差异显著(P<0.05);空载体组与单纯FMD灭活疫苗组上述3项指标间无显著差异。【结论】牛IL-18真核表达质粒在小白鼠体内得到了良好表达,且表达产物对FMD灭活疫苗的免疫效果具有明显的增强作用。

[Objective] The research was to ascertain the immunoenhancement effect on vaccine. [Method] The coding region sequenee of complete BOIL-18 gene was first inserted into peDNA3.1 vector, resulting in the construction of IL-18 gene eukaryotic expression plasmids （pcDNA3. 1-BOIL18）. Immunoenhaneement of the peDNA3-BoIL18 plasmid on Foot-and-Mouth Disease （FMD）Virus Vaccine was observed by the test of neutralizing antibody, proliferation response of the T lymphocytes from spleen, and the cytotoxicity of NK cells. At the same time,the pcDNA3.1-BOIL18 plasmid was distinguished from emp- ty pcDNA3.1 vector and FMD virus vaccine only. [Result] Proliferation responses of T and the eytotoxicity of NK cells were stronger than those of control group after 21st day plasmids and vaccines were significantly higher than those of mice only inoculated with vaecines after 28th day inoculation. But the mice inoculated with empty pcDNA3.1 vector and vaccines and vaccines only were not discrepant. [Conclusion] BOIL-18 has obvious immunoenhancement effects on Foot-and-Mouth Disease Virus Vaccine.