含乙型肝炎病毒S-PreS1 基因的DNA疫苗与蛋白颗粒疫苗联合免疫可增强免疫应答

Boosting with HBV subunit particle vaccine enhance immune response of novel DNA vaccine consisting of S-PreS1 fusion gene in mice

摘要:

为研制新型有效的HBV 治疗性疫苗，构建了含PreS1 与S 融合基因的HBV DNA 疫苗，即pVRC-HBSS1 (PreS121-47 aa 融合在S 抗原1-223 aa 的羧基端)，并制备了CHO 表达相同结构的蛋白颗粒亚单位疫苗HBSS1。在Balb/C 小鼠中采用不同的DNA 免疫方式 (即肌肉注射、皮内注射加电转) 初免3 次，蛋白颗粒亚单位疫苗 (不同佐剂) 肌肉注射加强免疫1 次，然后我们分析比较了各组疫苗所引起的免疫应答特点。抗体检测结果表明：皮内注射结合电转初免组产生的PreS1 与S 特异性抗体水平皆高于肌肉直接注射组。进一步还发现DNA 疫苗与蛋白颗粒亚单位疫苗两种疫苗联合应用后S 抗原特异的细胞免疫应答 (IFN-γ ELISpot 分析) 明显高于DNA 疫苗或蛋白颗粒亚单位单独应用，其中皮内注射+电转结合蛋白颗粒亚单位疫苗联合免疫组可产生最强的细胞免疫应答。这些研究为新型HBV 治疗性疫苗的优化设计与合理应用提供了依据。

Abstract:

To develop novel and effective HBV therapeutic vaccine, we constructed an expression vector, pVRC-HBSS1, in which PreS1 (21?47aa) coding gene fused to the C-terminal of the S (1?223 aa) coding gene of HBV, and prepared the protein particle vaccine HBSS1 that consist of S and PreS1 fusion antigen derived from CHO system. We immunized mice by priming three times with DNA vaccine via different methods (i.e., intramuscular injection, intradermal injection with electroporation), then boosting once with protein particle vaccine. We analyzed the immune response among various vaccination groups. The higher level of S or PreS1 specific antibodies was detected in the group via intradermal injection with electroporation, compared with that of direct intramuscular injection. We further found that the specific cellular immune responses (IFN-γ ELISpot analysis) in the group priming with DNA vaccines and boosting with protein subunit vaccine particles, was significantly higher than that of the DNA or protein particle subunit alone. Moreover, combination vaccination priming with intradermal injection DNA via electroporation and boosting with protein particle induced the strongest cellular immune response. These results provide a basis for rational design and application of the novel HBV therapeutic vaccine.