羊IL-2和OrfV-F1L基因疫苗联合免疫小鼠的免疫应答研究

Study on immune response in mice inoculated jointly with IL-2 gene vaccine and OrfV-F1L gene vaccine

为评价pVAX1-IL-2和pVAX1-F1L联合免疫小鼠诱导的体液和细胞免疫应答,分别将pVAX1-F1L+pVAX1-IL-2、pVAX1-F1L、pVAX1空载体、PBS对照组通过后腿肌肉注射的方式免疫KM系小鼠,采用ELISA方法检测免疫小鼠血清中OrfV特异性抗体以及Th1型(IL-2、IFN-γ和TNF-α)、Th2型(IL-4、IL-6和IL-10)细胞因子;MTT法检测小鼠脾淋巴细胞增殖反应。结果显示,pVAX1-F1L+pVAX1-IL-2联合免疫组小鼠血清抗体效价及IL-2、IFN-γ和TNF-α细胞因子水平均显著高于pVAX1-F1L组,与pVAX1组、PBS组相比差异极显著(P<0.01);pVAX1-F1L+pVAX1-IL-2联合免疫组小鼠血清IL-4、IL-6和IL-10细胞因子水平均显著高于pVAX1组和PBS组,与pVAX1-F1L组相比差异不显著(P>0.05);且pVAX1-F1L+pVAX1-IL-2免疫组的脾淋巴细胞增殖水平高于pVAX1-F1L组、pVAX1组和PBS组(P<0.01)。结果表明,pVAX1-IL-2和pVAX1-F1L联合免疫小鼠,能诱导小鼠产生OrfV特异性体液免疫和细胞免疫,pVAX1-IL-2诱导的免疫反应以细胞免疫应答为主,且能促进Th1型细胞因子的分泌。

To evaluate the humoral and cellular immune responses induced in mice co-immunized with pVAX1-IL-2 and pVAX1-F1L,KM mice were immunized with pVAX1-F1L+pVAX1-IL-2,pVAX1-F1L,pVAX1 empty vector and PBS control group by intramuscular injection of the hind leg,respectively.ELISA was used to detect OrfV-specific antibodies and Th1 type(IL-2,IFN-γand TNF-α)and Th2 type(IL-4,IL-6 and IL-10)cytokines in the serum of the immunized mice.Splenic lymphocyte proliferation in the mice was detected by the MTT assay.In result,the serum antibody titers and levels of IL-2,IFN-γ,and TNF-αcytokines in the mice immunized with pVAX1-F1L+pVAX1-IL-2 were significantly higher than those in the pVAX1-F1L group,compared with the pVAX1 group and the PBS group.The difference between the groups was extremely significant(P<0.01).The levels of serum IL-4,IL-6,and IL-10 cytokines in the pVAX1-F1L+pVAX1-IL-2 combined group were significantly higher than those in the pVAX1 group and the PBS group.Compared with the pVAX1-F1L immunized group,the difference was not significant(P>0.05);and the pVAX1-F1L+pVAX1-IL-2 immunized group had higher levels of spleen lymphocyte proliferation than the pVAX1-F1L immunized group,the pVAX1 group and the PBS group(P<0.01).The mice immunized with pVAX1-IL-2 and pVAX1-F1L could induce OrfV-specific humoral and cellular immunity.The immune responses induced by pVAX1-IL-2 were mainly cellular immune responses,which promoted the secretion of Th1 cytokines.The above-mentioned results provide the basis for further development of OrfV nucleic acid vaccines.