FIG. 1.

LGP2 is a feedback inhibitor of the antiviral system. (A and B) HeLa (A) or 2fTGH (B) cells were treated with 1,000 U/ml IFN-α or poly(I:C) {both extracellular [dsRNA (M)] and intracellular [dsRNA (Tx)] } or infected with Sendai virus (MOI = 1) for the indicated time course. Total RNA was isolated from cells and subjected to reverse transcriptase (RT)-PCR with the gene-specific primer sets indicated. (C and D) HeLa (C) or 2fTGH (D) cells were transiently transfected with the −110 IFNβ-luc reporter gene and the indicated RNA helicase vector. The cells were mock treated (control) or transfected with poly(I:C) for 6 h [dsRNA (Tx)]. (E) 2fTGH cells transfected with the LGP2 expression vector or empty vector (vector) along with the −110 IFNβ-luc reporter gene were mock treated or infected with Sendai virus (MOI = 1) for 12 h. (F) Similar analysis as for panel E was carried out with the 3× PRD III/I luc reporter gene. (G) Similar analysis as for panel E was carried out with the 4× PRDII luc reporter gene. In all cases, the data were normalized to results for the cotransfected Renilla luciferase reporter and the bars indicate the average (n = 3) ± the standard deviation, plotted as the percent control for each reporter gene. SeV, Sendai virus.