Fig 1: PKR deletion does not affect the innate immune response or cell viability. A549 WT or PKR−/− cells infected with DENV4 (MOI 2) or ZIKV (MOI 3) and harvested at 24 h.p.i. for analysis. (A) Quantification by RT-qPCR of IFNβ, IFNλ, ISG15, and TNF-α gene expression. Relative expression calculated by 2−ΔΔCt methods using mock cells as a reference. (B) Immunoblot analysis of cell extracts resolved in denaturing SDS-PAGE. Representative image of two independent experiments. (C) Flow cytometry analysis for quantification of living cells by staining with Zombie NIR viability dye. Mock WT cells set as 100% reference. In the column charts, bars represent the means ± standard error of the mean from three independent experiments. Statistical analysis was performed by paired t test comparing the two cell lineages under the same conditions. *P ≤ 0.05. ns/no markup, no statistical difference.