FIGURE 1.

Suppression of HBV infection by IL-1β. A, upper graph, HepaRG cells were pretreated with cytokines at 100 ng/ml (except for IFNα and IFNβ at 100 IU/ml) or heparin at 25 units/ml as a positive control or were left untreated (control) for 3 h and then infected with HBV in the presence of each stimuli for 16 h. After washing, cells were cultured in normal growth medium for 12 days. HBs protein secreted into the medium was quantified by ELISA. Lower scheme indicates the treatment procedure for HepaRG cells. Black and dashed line boxes indicate the periods with and without treatment, respectively. B–G and I, HepaRG cells (B–G) or PHH (I) were treated as shown in A with or without 100 ng/ml IL-1β or 25 units/ml heparin as a positive control. HBc protein in the cells (red) was detected by indirect immunofluorescence analysis, and the nucleus was stained with DAPI (blue) at 12 days post-infection (B). HBV DNA (C and I), cccDNA (E), and HBV RNA (F) in the cells as well as HBV DNA in the medium (D) were detected. Cell viability was quantified by MTT assay (G). HBV(−) in I indicates uninfected cells. All of the data, except in I, are based on the average of three independent experiments. I shows the average results from one representative experiment, but the reproducibility of the data were confirmed in three independent experiments. H, reporter plasmid carrying the HBV core promoter was transfected with HepG2 cells and then treated with or without IL-1β (1, 10, and 100 ng/ml) and an retinoid X receptor antagonist HX531 as a positive control for 6 h. Luciferase activity was measured.