DNA疫苗诱导健康小鼠抗-HBs产生的实验研究

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(preS

Humoral immune response induced by HBV DNA vaccine in healthy mice

Objective To evaluate the humoral immunity induced by HBV DNA vaccine in healthy mice. Method Two eukaryotic expressed plasmids namely pS2. S and pFP, encoding HBV middle protein ( preS2 + 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 2nd 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 pS2. 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 2nd week, which is significantly higher than that (21.0 ± 7.17)mIU/ml of the control (pS2. 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.