IL-15真核表达质粒的构建及对乙肝疫苗诱导的体液免疫应答的影响

目的 研究两种不同的IL-15真核表达质粒对乙肝蛋白疫苗诱导的免疫应答的影响。方法：构建IL-15真核表达质粒(简称pIL-15)和含有IL-12信号肽的IL-15真核表达质粒(简称pIL-2s-15)，CTLL-2细胞增殖实验验证两种质粒真核表达产物的生物学活性。将这两种质粒分别与HBsAg共免疫BALB／C小鼠，用ELISA法检测小鼠血清抗-HBs IgG及IgGl、IgG2a亚类的效价。结果：与HBsAg蛋白疫苗共免疫时，pIL-15可使HBsAg诱导的抗-HBsIgG效价升高，显著高于载体pcDNA3．1与HB—sAg共免疫对照组，pIL-2s-15对HBsAg诱导抗-HBsIgC效价没有明显影响。与HBsAg pcDNA3．1组相比，HBsAg pIL-2s-15组和HBsAg pIL-15组诱生的抗HBsIgG2a亚类均升高，但前者IgG2a／IgG1比值最高，与HBsAg pcDNA3．1组相比差别有显著性；HBsAg pIL-15组IgG2a／IgG1比值与HBsAg pcDNA3．1组相比差别无显著性。结论 pIL-15真核表达质粒可增强蛋白疫苗诱导的体液免疫应答，pIL-2s-15真核表达质粒则主要使免疫应答趋向Th1型。

Cloning of two different IL-15 genes and their effect on the humoral immune response elicited by HBV vaccine

Objective:To study the effect of IL-15 eukaryotic expression plasmid on the humoral immune responses to HBV surface antigen protein vaccine.Methods:Had constructed two of IL-15 eukaryotic expression plasmides.One is the eukaryotic expression plasmid of the IL-15 whole sequence,the other is the chimeric eukaryotic expression plasmid of the IL-2 signal peptide and IL-15 mature peptide sequence(IL-2s-15).The bioactivities of the expression products of the two plasmids were identified by CTLL-2 proliferation assay.Results:After IL-15 plasmid co-immunized with HBsAg,the titer of anti-HBsIgG was much higher than that of control( P <0.05),but when IL-2s-15 plasmid co-immunized with HBsAg,the titer of anti-HBsIgG was not much different from vector pcDNA3.1 co-immunized with HBsAg( P >0.05),however,the anti-HBsIgG2a/IgG1 ratio was higher than that of control.Conclusion:IL-15 expression plasmids effect differently on the immune responses induced by protein vaccine.