FIG. 3.

The replication of vK1L⁻C7L⁻/GFP⁺ is inhibited by treating the cells with hIFN-β before but not during the infection. (A) hIFN-β was effective at inhibiting vK1L⁻C7L⁻/GFP⁺ replication only when it was added to the cells before the infection. Huh7 cells were left untreated (−) or were treated (+) with 200 U/ml of hIFN-β before and/or during the infection, as indicated. The cells were infected at an MOI of 5, and viral yields at 24 hpi were determined by plaque assay. (B) The yield of vK1L⁻C7L⁻/GFP⁺ is inversely related to the length of time the cells were pretreated with hIFN-β. Huh7 cells were treated with 200 U/ml of hIFN-β for 0, 2, 4, 6, 8, or 24 h before they were infected with vK1L⁻C7L⁻/GFP⁺ or WT-GFP⁺ at an MOI of 5. Viral yields at 24 hpi were determined by plaque assay.