DNA疫苗诱导健康小鼠抗-HBs产生的实验研究

Humoral immune response induced by HBV DNA vaccine in healthy mice

目的 初步评价DNA疫苗诱导健康小鼠体液免疫应答效果。方法 应用基因重组技术构建编码乙型肝炎病毒 (HBV)中蛋白 (preS2 +S)及人白细胞介素融合蛋白 (FP)基因真核表达质粒(pS2 .S/ pFP) ,按不同剂量一次性及联合应用肌内注射免疫小鼠。 结果 HBVDNA疫苗 (pS2 .S)高(10 0 μg/只 )、中 (5 0 μg/只 )、低 (10 μg/只 )三组剂量一次性免疫健康C5 7BL/ 6小鼠均能在 2周诱导抗 HBs产生 ,抗体效价随时间延长而增长。血清抗体水平比较 ,高剂量组 (82 .9± 30 .0 )mIU/ml较中剂量组 (4 2 .2± 2 5 .6 )mIU/ml、低剂量组 (2 4.6± 7.5 )mIU/ml差异分别具显著性 (P <0 .0 5 )及非常显著性 (P <0 .0 1)。以后的 4、8、14周高、中剂量组间差别缩小 ,但二者较低剂量组差异均具非常显著性 (P <0 .0 1)。低剂量组 (10 μg/只 )的 pS2 .S与 pFP联合免疫 ,于 2、4周诱导组内全部 (10 0 % )健康小鼠抗体产生 ,而相同剂量的 pS2 .S +pcDNA3.1组仅分别为 6 0 %及 80 %。联合免疫组 2周血清抗体水平 (115 .6± 2 1.6 )mIU/ml较 pS2 .S +pcDNA3.1组 (2 1.0± 7.7)mIU/ml差异有显著性 (P <0 .0 5 )。结论 本室构建的HBVDNA疫苗能有效诱导正常小鼠体液免疫应答 ;联合接种白细胞介素融合蛋白质粒能有效增强DNA疫苗的免疫效?

Objective To evaluate the humoral immunity induced by HBV DNA vaccine in healthy mice. Method Two eukaryotic expressed plasmids namely pS 2.S and pFP, encoding HBV middle protein(preS 2+S) or cytokine fusion protein by genetic recombinant technique and immunized the healthy mice by direct intramuscular injection. Results In the healthy C57BL/6 mice, serum anti HBs appeared at the 2 nd week after DNA vaccination, and quantitative comparison of the serum Ab level revealed a significant( P <0.05 ) or very significant( P <0.01) difference between the high dose group(82.9±30.0) mIU/ml and the median dose(42.2±25.6) mIU/ml or the lower dose (24.6±7.5) mIU/ml respectively. During the long term follow up, the difference between the high and median dose group became less remarkable, whereas it remained to be very significant as they compared with the lower dose group. Co delivery of pFP(10 μg/mice) with pS 2.S(10 μg/mice) resulted in an Ab positive rate of 100%, with its serum anti HBs level of 115.6±21.6 mIU/ml at the 2 nd week, which is significantly higher than that (21.0±7.17) mIU/ml of the control (pS 2.S+pcDNA3.1). Conclusion The plasmids we constructed are effective to induce humoral immune response in healthy mice and codelivery of cytokine fusion protein may enhance the immunity of the HBV DNA vaccine.