Fig. 1: SAMD9 overexpression activates IFN signaling in a MAVS-TBK1-IRF3 dependent manner.

A A volcano plot of RNA sequencing results indicating top gene transcripts upregulated (red) and downregulated (blue) by SAMD9 overexpression as compared to empty vector (Ev) transfection in A549 cells. B–D A549 cells transfected with Ev or SAMD9-Myc-DDK plasmid for 24 h and the mRNA levels of IFNL3, CCL5, and CXCL10 measured by qRT-PCR (B), and levels of secreted IFN-λ3 (C) or CCL5 (D) quantified by ELISA. E Validation of wild-type (WT), single clonal MAVS KO, TBK1 KO A549 cells by western blot with indicated antibodies. F, G WT, single clonal MAVS KO and TBK1 KO A549 cells transfected with Ev or SAMD9-Myc-DDK plasmid for 24 h and the mRNA levels of IFNL3 (F) and CCL5 (G) measured by qRT-PCR. H A549 cells transfected with Ev or SAMD9-Myc-DDK plasmid for 24 h, and cell lysates harvested for SDS-PAGE electrophoresis with indicated antibodies. I, J A549 cells incubated with ruxolitinib (10 μM) for 1 h, transfected with Ev or SAMD9-Myc-DDK for 24 h and the mRNA levels of IFNL3 (I) and CCL5 (J) measured by qRT-PCR. The RNA sequencing experiment in (A) was performed once in duplicate, other experiments were repeated at least three times. Individual points in (B–D, F, G, I, and J) represent independent experiments. Data are represented as mean ± SEM. Statistical significance calculated by two-way ANOVA with Sidak’s multiple-comparisons tests (B, F, G, I, and J), or unpaired two-tailed Student’s t-test (C, D): n.s., not significant, *P < 0.05, **P < 0.01, ***P < 0.001. Source data are provided as a Source Data file. Detailed P-values are provided in the Source Data file.