目的构建可同时表达绿荧光蛋白（GFP）和针对HBVS区基因的小干扰RNA（siRNA）的重组腺病毒，并研究该siRNA在体外对HBV的抑制作用。方法采用PCR技术自质粒pEGFP-C1中扩增含CMV启动子的GFP表达框，自质粒pAVU6＋4sh579中扩增含U6启动子的针对HBV S 区579-597位基因的siRNA表达框，分别将两个表达框克隆至穿梭载体质粒pShuttle内，与质粒pADEasy-1在大肠杆菌BJ5183内进行同源重组，将阳性重组体DNA转染至人胚肾细胞株HEK293细胞中进行包装、扩增，并在HepG2.2.15细胞中初步观察其对HBV复制的抑制疗效。结果构建了可同时表达GFP和siRNA的重组腺病毒，其可在HEK293细胞中进行包装、扩增，并在HepG2.2.15细胞中对HBV-DNA、HBsAg和HBeAg的表达具有抑制作用。结论成功构建了可同时表达GFP和针对HBV的siRNA的重组腺病毒，并在体外实验中证实了其对HBV复制具有抑制作用。
Objective: To construct a cDNA library from human liver tissue with chronic hepatitis B and check its quality for investigating the expression level of liver tissue infected by hepatitis B virus. This will then be used to find the relevant genes and interesting proteins associated with the development of hepatitis B. Methods: The total RNA from liver tissue with chronic hepa- titis B was extracted and the mRNA was purified using TRIZOL method. Switching mechanism at 5′ end of the RNA transcript (SMART) technique and CDS III/3′ primer were used for first-strand cDNA synthesis. Long distance polymerase chain reaction (LD PCR) was then used to synthesize the double-strand cDNA that was then digested by Sfi I and fractionated by CHROMA SPIN-400 column. The longer than 0.4 kb cDNAs were collected and ligated to λTriplEx2 vector. Then λ phage packaging reaction and library amplification were performed. The qualities of both unamplified and amplified cDNA libraries were strictly checked by conventional titer determination. Fourteen plaques were randomly picked and tested using PCR with universal primers derived from the sequence flanking the vector. Results: The titers of unamplifed and amplified libraries were 1.94×106 pfu/ml and 1.49×109 pfu/ml respectively. The percentages of recombinants from both libraries were 98.15% in unamplified library and 98.76% in amplified library. The lengths of the inserts were 1.23 kb in average, 1?2 kb in 64.29%, and 0.5?1.0 kb in 35.71%. Conclusion: A high quality cDNA library from human liver tissue with chronic hepatitis B was successfully constructed.
