Fig. 1

MST4 negatively regulates the production of RLR-mediated type I IFNs. A, B Luciferase activity in the lysates of 293 T cells transfected with IFN-β luciferase reporter (IFN-β-Luc), β-gal, and increasing concentrations of the Myc-MST4 expression plasmid (0, 50, 100, 200 ng) for 24 h and then treated or untreated with Poly (I:C) transfection (A) or SeV infection (B) for 8 h. Results are presented compared to the luciferase activity in the control cells treated with a luciferase reporter and empty vector. C Immunoblot analysis of MST4 in 293 T cells infected with lentiviruses carrying sh-MST4 1# and sh-MST4 2# (performed to generate stable cell lines), followed by infection with SeV for 8 h. D, E Luciferase activity in the lysates of 293 T-sh-Control and 293 T-sh-MST4 cells transfected with IFN-β-Luc, and transfected with Poly (I:C) (D) or infected with SeV (E) for 8 h. F, G Quantitative PCR analysis of the mRNA levels of IFNB1, IFIT1, and IFIT2 in 293 T-sh-Control and 293 T-sh-MST4 cells transfected with Poly (I:C) (F) or infected with SeV (G) for 8 h. H ELISA results of IFN-β production in the supernatants of 293 T-sh-Control and 293 T-sh-MST4 cells transfected with Poly (I:C) or infected with SeV for 12 h. Data information: The data are represented as mean ± SD (A, B, D–H: n = 3). *P < 0.05, **P < 0.01, and ***P < 0.001 (unpaired two-tailed Student’s t-test). The data are representative of at least three independent experiments