Rapid induction of antiviral ISG mRNAs following RdRP expression in human lung epithelial cells.

(A) DOX-inducible RdRP A549 cell lines were generated using lentiviral vectors that inducibly co-express RdRP or RdRPΔcat and resistance to puromycin. Vector terminology: Tsin-TetON-RdRP-IRESpuro (TetON-RdRP) and Tsin-TetON-RdRPΔcat-IRESpuro (TetON-RdRPΔcat) lentiviral vectors. (B) TetON-A549 cell lysates were analyzed by immunoblotting to determine relative abundance of RdRP-HA protein (anti-HA-tag) following DOX treatment (hr). (C) mRNA levels of the prominent antiviral genes, IFI27, OASL, ISG15, IFIT1,and IFNβ in TetON-A549 cell lines prior to (0 hr) or after (24 and 48 hr) DOX treatment (data are mean ± SEM of three technical replicates, relative to GAPDH mRNA). * P.05; ** P.01; *** P.001; **** P.0001.