Figure 3.

DHX9 attenuates the anti-HBV function of A3B in loss- and gain-of function experiments. (A) Huh7 cells were transfected with siRNA targeting A3B and then cotransfected with Flag-DHX9 and the HBV expression plasmid. Viral DNA was measured by qPCR. (B) Huh7 cells were first transfected with siRNA targeting DHX9 or control siRNA first and then cotransfected with HA-A3B expressing plasmid and HBV expression plasmid (ratio = 3:1). After 3 days, HBV DNA levels in cytoplasmic fractions were measured by qPCR, and the expression of the DHX9 and A3B proteins was analysed by Western blotting. (C) The intracellular HBV DNA in HepAD38 cells was extracted and measured by Southern blot. (D) HepG2-NTCP cells were transfected with HA-A3B alone or together with the Flag-DHX9 plasmid, followed by infection with HBV particles for four days. The viral DNA levels were measured by qPCR. RC: relaxed circular; DL: double-stranded linear; SS: single stranded. The mean ± SD of three experiments is represented. Statistical significance was determined by one-way ANOVA with Tukey’s post hoc test (*p < 0.05, **p < 0.01, ***p < 0.001).