FIG 2.

ISRE-dependent cytokine augmentation of the IFN response. (A and B) Huh-7 cells were transfected with either ISRE-linked or ISRE-mutant (Mut)-linked EGFP reporter constructs. After 20 h of incubation, the cells were treated with 1 nM each selected cluster cytokine in the presence (A) or absence (B) of 10 U/ml IFN-α. pA denotes 3′ UTR poly(A) signal. (C) Cytokine modulation of the IFN response. Huh-7 cells were transfected with ISRE-linked reporter constructs for 20 h. The cells were then treated with increasing log_0.5 doses of IFN-α in the absence or presence of the indicated cytokines (1 nM each). The data shown are mean (±SEM) fold increases in fluorescence activities (pixels), compared to IFN alone, from one representative experiment out of two. The P values were determined by two-curve comparison by F test. *, P < 0.05; **, P < 0.01; ***, P < 0.001.