CTNNB1 is a negative regulator of antiviral innate immunity.

<p>(A) <i>IFNB1</i> promoter-driven luciferase activity in HEK 293T cells transduced with lentivirus-expressing shRNA NT (control) or 3 shRNAs targeting CTNNB1 for four days and subjected to SeV infection for 16 hours. (B) Immunoblot analysis of CTNNB1 and IFIT1 in HEK 293T cells transduced with 3 lentivirus-expressing shRNAs targeting CTNNB1 and infected with SeV. (C) Immunoblot analysis of CTNNB1, IFIT1 and DDX58 in SeV-infected HEK 293T cells previously transduced with a shRNA or transfected with a pool of four siRNAs targeting CTNNB1 for three days. (D–F) Fold induction of <i>IFNB1</i> (D), <i>DDX58</i> (E) and <i>TNF</i> (F) mRNA levels in HEK 293T cells treated as described in (C). qRT-PCR determination represents the average mRNA RQ normalized versus ACTIN and HPRT1 mRNA. (G) ELISA quantification of secreted IFN-β protein in supernatant of HEK 293T cells treated as described in (A). (H–I) Fold induction of <i>IFNB1</i> promoter-driven luciferase activity (H) and of CTNNB1-TCF/LEF dependent reporter activity (TOP-flash, I) following dose-dependent transfection of CTNNB1-expressing plasmid (50, 100, 150 and 200 ng) for 48 hours in SeV-infected HEK 293T cells.