表达猪瘟病毒E2蛋白的重组腺病毒的构建及其在兔体内的免疫原性分析

Generation and Immunogenicity of a Recombinant Adenovirus Expressing the E2 Protein of Classical Swine Fever Virus in Rabbits

摘要:

为了构建猪瘟重组腺病毒载体疫苗, 通过细菌内同源重组法构建了含有猪瘟病毒E2基因的重组腺病毒rAdV-E2。测定其一步生长曲线, 同时用间接免疫荧光试验和Western blotting检测外源基因表达, 然后用rAdV-E2免疫家兔, 免疫后6 w用猪瘟兔化弱毒疫苗株(C株)进行攻击, 攻毒后3 d取其脾脏, 用实时荧光定量RT-PCR检测C株病毒RNA。结果表明, 该重组腺病毒传至第10代时, 毒价可达1.0×1010 TCID50/mL; 外源基因可在其中得到稳定表达; rAdV-E2接种兔免疫后2 w产生猪瘟特异性抗体, 免疫后5 w抗体达到峰值, 攻毒后rAdV-E2接种兔和C株接种兔均未出现定型热反应, 从其脾脏也未检测到C株病毒RNA, 而野生型腺病毒接种兔均出现了定型热反应, 并且从其脾脏检测大量C株病毒RNA, 其含量达到了103拷贝/mL以上。由此表明, rAdV-E2可望开发为猪瘟候选疫苗。

Abstract:

Classical swine fever (CSF), which is caused by classical swine fever virus (CSFV), causes significant losses in pig industry in many countries in Asia and Europe. The E2 glycoprotein of CSFV is the main target for neutralizing antibodies. In this study, a recombinant replication-defective human adenovirus expressing the CSFV E2 gene (rAdV-E2) was generated and evaluated for the immunogenicity in rabbits. The results showed that the rabbits immunized with rAdV-E2 developed high-level CSFV-specific antibodies. The rAdV-E2-immunized rabbits were all free of the regular fever and the viral replication in the spleen upon challenge with C-strain, which were seen in the rabbits immunized with the parent adenovirus of rAdV-E2. This indicates that the recombinant adenovirus can be an attractive candidate vaccine against CSF.