Figure 5

IFNAR1 protein expression complements the ISRE-firefly luciferase promoter activation in the resistant Huh-7 cells. The cured resistant Huh-7 cell line (R-17/3) was co-transfected with ISRE-firefly luciferase plasmid along with each expression plasmid by FuGene6 transfection reagent. The pRL-TK plasmid was used as a transfection control. After this step, cells were treated with IFN-α (1000 IU/ml). After 24 hours, cells were lyzed and luciferase activity was measured. The graphs represent a relative to control luciferase activity. (A) The activation of ISRE promoter by IFN-α in R-17/3 cells expressing different proteins of Jak-Stat signaling expressed as relative luciferase units (RLU) between IFN-α treated and untreated. Expression of wild type full-length IFNAR1 protein is able to induce the ISRE-Luciferase activity. (B) The induction of ISRE-luciferase activity in the R-17/3 cells by IFN-α in the presence of three different variants of IFNAR2 and wild type IFNAR1 was depicted as fold increase as compared to untreated cells. (C) IFN-α induces the ISRE-Firefly luciferase activity (fold increase) in all nine IFN-α resistant Huh-7 cell lines when they were co-transfected with the wild type IFNAR1 plasmid.