Study of the different HBV replication in HepG2.2.15 cells treated with lamivudine or sequentially treated with lamivudine and interferon-α / 中华检验医学杂志

ABSTRACT

Objective To investigate the characteristics of HBV replication in HepG2.2. 15 cells treated with LAM alone or sequentially treated with LAM and IFN-α, and to further explore the different suppressive effect on HBV replication by LAM and IFN-α in vitro. Methods Untreated HepG2. 2. 15 cells were used as control group, HepG2. 2. 15 cells treated with 1 000 IU/ml of IFN-α alone for 10 d were served as IFN-α group. The HepG2.2. 15 cells treated with 0.2,1,5,20,100 μmol/L of LAM were used as LAM groups. HepG2. 2. 15 cells treated with 0. 04,0. 2,5,25,125,200 μmol/L of LAM for 7 d, then combined with 1 000 IU/ml of IFN-α for another 3 d. Afterwards, the cells were treated with 1 000 IU/ml of IFN-α only for another 10 d. These cells were served as LAM/IFN-α sequential treatment group. The ELISA was used for analyzing the secreted HBV antigens, while the Dot blot, Southern blot were applied for analyzing the extracellular HBV DNA and intracellular HBV replicative intermediate DNA in HepG2. 2. 15 cells of different treatment groups. Results The secreted HBsAg in the LAM group were 1. 77 ± 0. 22, 1.65 ±0.25, 1.95 ±0. 19, 1.34 ±0. 11, 1.07 ±0.05, respectively, and the secretion of HBeAg were 1.41 ±0. 13, 1.37 ± 0. 09, 1.63 ± 0. 07, 1.26 ± 0. 12, 1.05 ± 0. 09. The secreted HBsAg and HBeAg in control group were 3. 34 ± 0. 15 and 3.33 ± 0. 05. Statistical analysis showed that HBsAg and HBeAg secretion in the LAM group were significantly reduced by treatment with LAM. The t values of HBsAg were 10. 21,10.04, 9.94, 18.62, 24.86, and the t values of HBeAg were 23.87, 32.97, 34.22, 27.57, 38.35,respectively, all P values were ＜ 0.05. Dot blot, Northern blot hybridization analysis indicated that the extracellular HBV DNA and intracellular HBV replicative intermediate DNA could not be detected in the LAM group after cells treated by LAM for 10 days. When LAM was replaced with treatment of 1 000 IU/ml of IFN-α alone, it could not suppress the HBV replication effectively. Moreover, the intracellular HBV replicative intermediate DNA still existed in almost all groups, accompanied with the recovered expression of HBV antigens as well as extracellular HBV DNA, which suggested that the HBV particles restored replication again and secreted extracellular in HepG2. 2. 15 cells, although the sequential treatment lasted for 10 days.Conclusion The effect of viral suppression by LAM and IFN-α in vitro were different, which attributed to the different HBV replicative characteristcs in HepG2. 2. 15 cells.