FIG. 1.

PKR is required for maximal induction of IFN-β by measles virus V and C mutants. (A) IFN-β mRNA normalized to GAPDH was measured using quantitative real-time PCR as described previously (15), utilizing reverse-transcribed total cellular RNA prepared from uninfected mock or MV-infected (WT, V^ko, or C^ko) (MOI of 5) PKR^kd-con and PKR^kd cells at 10, 16, and 24 h postinfection. Error bars indicate the standard deviations of data from three independent experiments. *, P < 0.01. (B) Template dilution analysis with cDNA prepared from uninfected mock (open symbols) or C^ko-infected (24 h) (filled symbols) PKR⁺ parental cells with primer pairs for IFN-β (triangles) or GAPDH (circles).