猪IL-2对pcDNA-E39.VP2真核共表达质粒免疫原性的影响

Effect of immunogenicity of the pig interleukin 2(IL-2)on co-expression DNA vaccine with JEV E39-PPV VP2

为了研究猪IL-2基因的真核质粒和融合基因形式对pcDNA-E39.VP2真核共表达质粒的免疫增强作用,分别将IL-2基因插入pcDNA3.1(+)和pcDNA-E39.VP2(已构建)中构建重组质粒pcDNA-IL2和pcDNA-IL2-E39.VP2。将真核质粒pcDNA-IL2-E39.VP2免疫小鼠,另外,将pcDNA-IL2分别先于和后于pcDNA-E39.VP2 3d免疫小鼠,同时设pcDNA-E39.VP2对照组。对免疫小鼠进行PPV(JEV)抗体水平、脾脏淋巴细胞增殖功能和外周血T淋巴细胞亚群变化的检测。结果显示,1周后,pcDNA-IL2-E39.VP2免疫组和pcDNA-IL2后于pcDNA-E39.VP注射的免疫组JEV/PPV抗体水平和脾脏淋巴细胞增殖活性显著(P<0.05)或极显著(P<0.01)高于对照组,pcDNA-IL2先于pcDNA-E39.VP注射的免疫组仅在第5周显著(P<0.05)高于对照组;各组(除对照组外)CD8+值差异不显著(P>0.05),CD4+、CD4/CD8值都高于对照组,其中pcDNA-IL2-E39.VP2免疫组与对照组差异极显著(P<0.01)。结果表明,IL-2能增强pcDNA-E39.VP诱导小鼠的免疫能力,且以融合基因形式构建的真核质粒免疫增强效果最明显。

In order to compare the immt]ne enhancement of the pig interleukin 2（IL-2）on co-expression plasmid pcDNA-E39. VP2 in the form of eukaryon expression plasmid and fusion gene, pig IL-2 gene was inserted into the ex- pression vector pcDNA3.1 （＋） and pcDNA-E39. VP2 to construct reorganization plasmid pcDNA-IL2 and pcDNA- IL2-E39. VP2. Then Balb/c mice were immunized with pcDNA-IL2-E39. VP2 and hybrid plasmid-pcDNA-IL2 were injected three days befor or after expression plasmid pcDNA-E39 VP2. At the same time,pcDNA -E39. VP2 DNA vaccine were set up as the control group. Anti-JEV/PPV antibodies,lymphocyte proliferation activity and the T lym- phocyte subsets were detected. The results showed that, the PPV/JEV antibody levels and the reaction of the splenic T lymphocytes to the ConA stimulation in pcDNA-IL2-E39. VP2 and pcDNA-IL2 injected after pcDNA-E39. VP were significantly （P〈0.05） or highly significantly （P〈0.01） higher than the control group after one week, pcD- NA-IL2 injected before pcDNA-E39. VP was significanly （P〈0.05） higher than control group at five weeks. The difference of CD8^＋ T lymphocytes between groups, except control group, were not significant （P〈0.05）. CD4^＋ T lymphocytes and CD4/CD8 ratio were both higher than control group, especially between pcDNA-IL2-E39. VP2 group and control group were highly significant （P〈0.01）. The results show that IL-2 can enhance the immunity of pcDNA-E39. VP,and the immunity enhancement effect of the fusion gene eukaryotie plasmid was most obvious.