FIG 1.

YFV does not inhibit IFN-α/β signaling in murine cells. (A) Vero cells were either mock infected or infected with YFV-17D at an MOI of 1. At 14 h postinfection, cells were mock treated or treated with 1,000 U/ml universal type I IFN for 12 h and then infected with NDV-GFP. NDV-GFP replication was monitored by fluorescence microscopy 14 h later. 293T (B) or Hepa1.6 (C) cells were infected with YFV-Asibi and YFV-17D at an MOI of 10 for 20 h and then treated with 100 U of universal type I IFN for 12 h. DENV2 (16681 strain) was used as a positive control. ISGs were measured by qRT-PCR as described in the Materials and Methods section. Fold change of the gene expression over the mock is plotted on the graphs. Statistical analysis was performed using unpaired, two-tailed t test versus mock-infected cells (**, P ≤ 0.01; ***, P ≤ 0.001; ****, P ≤ 0.0001). (D) Levels of Intracellular viral RNA over time by qRT-PCR following infection of 293T or Hepa1.6 cells with the indicated viruses.