FIG 10.

IFN antagonist activities of respective P protein isoforms to suppress IFN induction in muscle cells. (A) G-8 cells were transfected with a plasmid expressing each P protein isoform (pCAGGS-P1, -P2, -P3, -P4, or -P5) or N protein (pCAGGS-N), or an empty plasmid, together with IFNB-pGL3. The cells were transfected with poly(I·C) at 24 h posttransfection and incubated for 6 h. Cell lysates then were prepared and used to measure luciferase activities. GL, firefly luciferase activity; RL, Renilla luciferase activity. All assays were carried out in triplicate, and the values in the graph are shown as means ± standard errors of the means. *, Significant difference at a P value of <0.005. (B) P protein isoforms and N protein expressed in the above-described transfected cells were analyzed by Western blotting. Tubulin in each sample was also detected as a loading control.