Interferon-inducible ribonuclease ISG20 inhibits hepatitis B virus replication through directly binding to the epsilon stem-loop structure of viral RNA
(A) Hela, HepG2, and Huh7 cells were seeded in a 12-well plate for overnight, then left untreated or treated with human IFN-α (1,000 IU/ml) for 18 or 36 h. The untreated cells (control) were harvested together with the cells treated by IFN-α for 36 h. ISG20 expression was detected by Western blot. Hela cells transfected with plasmid F-ISG20 expressing the FLAG-tagged ISG20 were used as positive control for ISG20 Western blot (lane 2). β-actin expression was presented as loading control. (B) PHHs and HepG2 cells were cultured in 12-well-plate and treated with type I IFN-α (1,000 IU/ml), type II IFN-γ (100 ng/ml) or type III IFN-λ (100 ng/ml), or left untreated (control) for 2 days. The levels of ISG20 expression were determined by Western blot.