Fig. 3.

Activation of the IFN induction cascade by influenza virus is sensitive to actinomycin D but not cycloheximide. A549 cells were infected with 5 PFU/cell of an NS1-defective Udorn virus (Ud-Δ99; Jackson et al., 2010) or a DI-rich preparation of PIV5 (PIV5-VΔC vM2; Killip et al., 2011), in the presence of 1 μg/ml actinomycin D (ActD) or 50 μg/ml cycloheximide (CHX) or were left untreated (UT). At 16 h post-infection, cell lysates were prepared and probed for phospho-IRF3 (p-IRF3), total IRF3, viral proteins and actin.