含临床病毒株聚合酶逆转录酶区的乙肝病毒DNA稳定复制细胞系的构建

摘要

目的 构建含有临床病毒株聚合酶逆转录酶(RT)区的乙肝病毒(HBV) DNA稳定复制细胞系.方法 采用巢式PCR从患者血清扩增HBV DNA片段,利用片段置换反应将该片段克隆到HBV DNA复制载体,并在该载体上引入新霉素抗性基因,在确认该重组DNA体外可复制后,将其转染HepG2细胞,G418筛选,采用real-time PCR结合ELISA及Southern blot检测初筛和鉴定HBV DNA稳定复制细胞系.结果 从患者血清扩增出的HBV DNA片段nt55～1654被成功置换到HBV复制质粒pLL相应区域,得到质粒p11;新霉素抗性基因表达片段被克隆到p11中HBV DNA下游,获得质粒p11-neo,Southern blot检测证实p11-neo可支持体外复制；p11-neo转染HepG2后,经筛选鉴定,获得了可支持HBV DNA稳定复制的细胞系3-10.结论 建立了含有临床病毒株聚合酶RT区的HBV DNA稳定复制细胞系,real-time PCR结合ELISA有助于HBV DNA稳定复制细胞系的快速初筛鉴定.%Objective To establish a stable cell line that can replicate hepatitis B virus (HBV) DNA carrying the reverse transcriptase sequence derived from a clinical isolate. Methods Nested PCR was used to amplify the HBV DNA fragment from the serum. The fragment was cloned into a plasmid that can support HBV replication in vitro by fragment substitution reaction ( FSR) , followed by the cloning of the neomycin expressing fragment downstream from HBV DNA. G418 selection was conducted after the transfection of HepG2 cells with the recombinant DNA. Real-time PCR and enzyme linked immunosorbent assay (ELISA) were used to screen stable cell lines that can replicate HBV DNA, and the replication of HBV DNA by the cell line was confirmed by using Southern blot analysis. Results Fragment nt55-1654 amplified from the serum DNA was substituted to the plasmid pLL, generating the plasmid p11. The neomycin fragment was cloned into p11 , leading to the plasmid pll-neo, and pll-neo was confirmed to be HBV-replication-competent. A stable cell line named 3-10 that can replicate HBV DNA was obtained. Conclusions A stable cell line was established that can replicate HBV DNA carrying the reverse transcriptase sequence derived from a clinical isolate. Real-time PCR plus ELISA may help to rapidly screen out stable cell lines replicating HBV DNA.