Fig. 5.

Type I IFN-treatment after IPNV infection inhibits the induction of expression from an IFN-responsive promoter. CHSE-Mx10 cells containing a transgenic luciferase reporter gene under the control of the rainbow trout Mx promoter were used. The cells were left untreated or were treated with IFN-α1 24 h prior to IPNV infection, treated with IFN-α1 4 h p.i. or 10 h p.i. The cells were infected with IPNV at MOI 2 and 10. All treatments were set up in triplicates. (A) The cells were harvested for luciferase assay at 24 h p.i. and (B) at 48 h p.i. The results are presented as fold increase in expression of the luciferase reporter gene. The asterisks mark significant reduction in luciferase induction for the IPNV infected cells compared to their mock-infected controls. These data represent one of three repeated experiments which generated reproducible data. (C and D) Cell lysates used in the luciferase assay in A and B were subjected to Western blotting with an eEF2 antibody as a loading control to estimate the levels of total protein present in each sample.