OBJECTIVETo investigate the anti-HBV effect of fusion protein thymosin alpha1-interferon alpha (TA1-IFN) in vitro and to compare its effect with a combination of interferon alpha and thymosin alpha1.

METHODSAfter 2.2.15 cells were seeded for 24 hours, drugs of five serial concentrations (8000, 4000, 2000, 1000, 500 U/ml) were added to the wells, then the medium was changed every three days. After 2.2.15 cells were treated with drugs for 6 days, the medium was collected. The inhibitory rates on HBsAg and HBeAg were determined using Abbot kit, and the cytotoxicity of different drugs by means of MTT colorimetric assays was also observed.

RESULTSThe inhibitory rate of fusion protein on HBsAg, HBeAg was dose-dependent and reached the maximum at 8000 U/ml concentration. In the meantime, the inhibitory rates of fusion protein on HBsAg and HBeAg were 72.2% +/- 0.8% and 60.4% +/- 1.1% respectively, and the cell survival rate was 85.2% +/- 2.0%; In the corresponding concentration, the inhibitory rates of combination thymosin alpha 1 and interferon alpha on HBsAg and HBeAg were 40.0% +/- 0.7%, 34.5% +/- 3.2% respectively. The results showed significant statistical differences between them; cell survival rate 70.0% +/- 1.9%, and the difference of the results was also significant. Cytotoxicity of fusion protein was weaker than a combination of thymosin alpha 1 and interferon alpha.

CONCLUSIONFusion protein TA1-IFN exerted stronger anti-HBV effects in vitro. Its anti-HBV effects in vitro were stronger than the combination of thymosin alpha and interferon alpha, and its cytotoxicity was weaker than the combination of thymosin alpha and interferon alpha. Our studies provided important evidence for clinical research on TA1-IFN, and also brought new hope for hepatitis B therapy.