FIG. 5.

(A) Cytokines upregulate the STAT-3-dependent stimulation of HBV enhancer 1 in vivo . Huh-7 cells were transiently transfected with pHnLuc, pFPV3Luc, pFPV4′Luc, and p′SLuc reporter plasmids, followed by stimulation with EGF and IL-6 as described in Materials and Methods. The experiments were performed in duplicate. Luciferase activity is expressed as fold induction over the baseline level of activity observed during transfection of these vectors without EGF and IL-6 treatment. Each reporter plasmid is indicated below the graph. (B) Cytokine-mediated stimulation of HBV mRNA biosynthesis. Equal amounts of RNA from 2.2.1.5 cells either untreated or treated with EGF and IL-6 were analyzed by Northern blot analysis. RNA was transferred onto a nitrocellulose filter and probed with ³²P-labeled 48-bp HBV DNA representing the X gene. Lane 1, RNA before stimulation was used as control; lane 2, incubation with EGF (6 h); lanes 3 and 4, stimulation with IL-6 for 6 and 12 h, respectively. Arrows indicate the 3.5- and 2.3- and 2.1-kb HBV mRNA species.