Splicing of ERVWE1 transcripts in response to stimuli. (A) Relative levels of nonspliced and spliced ERVWE1 transcripts were measured in uninfected and influenza A/WSN/33 virus-infected (MOI = 0.5) CCF-STTG1 cells at 24 h postinfection, primary human fibroblasts at 48 h postinfection, and JEG-3 cells at 24 h postinfection. (Inset) CT values of assays for transcripts encoding β-actin and spliced ERVWE1 transcripts in uninfected JEG-3 cells shown for reference. (B and C) Relative levels of spliced ERVWE1 transcripts and transcripts encoding IFN-β measured in CCF-STTG1 cells treated with 10 μg/ml poly(I·C) (B) or CCF-STTG1 cells infected with influenza A/WSN/33 virus (MOI = 0.5 or 4) (C). Samples were collected after 6 h, 12 h, 24 h, and 48 h. ND, not detectable.