携带HSP70-HBsAg嵌合基因复制缺陷型重组腺病毒的制备

目的 构建表达乙肝病毒表面抗原(HBsAg)和热休克蛋白70(HSPT0)嵌合基因的复制缺陷型重组腺病毒载体.方法扩增结核分枝杆菌HSP70基因片段,亚克隆到穿梭质粒pAdTrack-CMV-HBsAg上,与5型腺病毒骨架质粒pAdeasy-1共同电转化到大肠埃希菌BJ5183内进行同源重组,经卡那霉素抗性筛选和酶切鉴定筛选出携带HBsAg-HSP70嵌合基因的重组腺病毒载体,用脂质体包裹Pac Ⅰ酶切线性化的重组质粒,转染到293细胞内进行重组腺病毒的包装.体外转染真核细胞,通过示踪基因绿色荧光蛋白表达的观察、RT-PCR和ELISA检测目的基因的表达.结果成功获得重组腺病毒质粒pAd-HBsAg-HSP70.重组质粒pAd-HBsAg-HSP70导入293细胞,经包装和二次扩大培养获得了具有感染能力的重组腺病毒颗粒Ad-HBsAg-HSP70,其病毒滴度达2×1012pfu/L,并能在真核细胞中有效表达目的基因.结论成功构建表达HBsAg-HSP70复制缺陷型重组腺病毒载体,为进一步开展HBV基因治疗研究提供实验基础.

Construction of replication-deficient recombinant adenoviral vector carrying HBsAg and HSP70 chimeric gene and its expression in vitro

OBJECTIVE: To construct a recombinant adenoviral vector carrying HBcAg-HSP70 chimeric gene by homologous recombination in bacteria and to detect its expression in vitro. METHODS: Heat shock protein 70 gene from Mycobacterium tuberculosis were amplified by PCR and were cloned to adenoviral shuttle plasmid pAdTrack-CMV-HBsAg. Then the resultant pAdTrack-CMV-HBsAg-HSP70 was cotransfected into BJ5183 bacteria with the plasmid pAdeasy-1. The adenoviral plasmid carrying HBsAg-HSP70 gene (pAd-HBsAg-HSP70) was generated with homologous recombination in bacteria and the adenoviruses were produced in 293 cells. Several kinds of mammal cells (293 cells and Vero cells) were infected with adenoviruses and the expression of HBsAg-HSP70 was detected by RT-PCR and ELISA in vitro. RESULTS: The adenoviral plasmids pAd-HBsAg-HSP70 were obtained by selection for kanamycin resistance and confirmed by restriction endonuclease Pac analyses. The recombinant adenoviruses Ad-HBsAg-HSP70 were packaged successfully in 293 cells. The titer of Ad-HBsAg-HSP70 was up to 2 x 10(12) pfu/L after the second passage of proliferation in 293 cells. HBsAg and HSP70 were expressed efficiently in mammal cells after infection. CONCLUSION: The recombinant adenoviruses expressing HBsAg and HSP70 were constructed successfully which can be used further in study of gene therapy for HBV.