SRP54 Negatively Regulates IFN-Beta Production and Antiviral Response by Targeting RIG-I and MDA5

摘要

Overexpression of SRP54 inhibits RLRs-mediated signaling. A HEK-293T cells (1 × 105) were co-transfected with indicated luciferase reporters (0.05 µg each) together with empty vectors or increased amounts (0/0.05/0.1/0.2 µg) of SRP54 expression plasmids. Twenty-four hours after transfection, cells were left uninfected or infected with SeV for 12 h before luciferase assays were performed. Cell lysate was collected for Western blot analysis. B HEK-293T cells (5 × 105) were transfected with an empty vector or SRP54 expression plasmid (1 µg). Twenty hours after transfection, cells were left uninfected or infected with SeV for 10 h before quantitative RT-PCR was performed. C HEK-293T cells (5 × 105) were transfected with empty vector or SRP54 expression plasmids (1 μg). After 24 h, cells were left uninfected or infected with SeV for the indicated times. Cell lysates were then analyzed by immunoblotting with the indicated antibodies. D Similar luciferase reporter assays as in (A) were performed except the IRF-1 promoter reporters were transfected and cells were treated with IFN-γ (0.1 µg/mL) for 12 h before luciferase reporter assays were performed. Cell lysate was collected for Western blot analysis. β-actin was used as internal control for Western blot assay. GAPDH was used as internal control for quantitative RT-PCR. Graphs show mean ± SD. n = 3. *P < 0.05, **P < 0.01, ***P < 0.001.