FIG. 4.

Immunofluorescence of dsRNA in A549 cells infected with WT or mutant HPIV1. A549 cells were transfected with poly(I:C) (0.02 μg/μl) (A) or infected with WT (B), F170S (C), or P(C−) (D) HPIV1 at an MOI of 5 for 24 h. HPIV1 P protein (red) was detected using a rabbit polyclonal anti-P antibody and a Texas Red-conjugated secondary anti-rabbit antibody. dsRNA (green) was detected with a mouse monoclonal anti-dsRNA antibody and an FITC-conjugated secondary anti-mouse antibody. (E) dsRNA and the HPIV1 P protein were examined as in panels A to D in A549 cells infected with WT, F170S, or P(C−) HPIV1 at an MOI of 5 for 24 and 48 h. (F and G) Quantitation of the number of cells in panel D with and without detectable dsRNA (F) or HPIV1 P protein (G) at 24 and 48 h. dsRNA levels are representative of two independent experiments.