TNF blockage suppresses TLR9 ligand-induced facilitation of HBV viral clearance. BALB/c mice were either intraperitoneally administered etanercept or were untreated on the day before pAAV/HBV1.2 hydrodynamic injection. Etanercept treatment was administered twice a week over the whole period. At 3 days after hydrodynamic injection, the mice were treated with TLR9 ligand or non-TLR9-binding control oligonucleotide. (a) Differences in titers of serum HBsAg (left) and serum HBV viral loads (right) of mice that did or did not receive etanercept were quantified. §P<0.05, Student's t-test, compared with the TLR9 ligand group. *P<0.05; **P<0.01, Student's t-test, compared with the non-TLR9-binding control group. (b) Kinetics of serum ALT in mice challenged with TLR9 ligand or non-TLR9-binding control in the presence or absence of etanercept were quantified. §P<0.05, Student's t-test, compared with the TLR9 ligand group. *P<0.05, Student's t-test, compared with the non-TLR9-binding control group. HBsAg, HBV surface antigen; HBV, hepatitis B virus; TLR, Toll-like receptor.