Cell culture media and supplements

Cell lines were purchased from American Type Culture Collection and cell culture media and supplements were purchased from Life Technologies, Inc., Carlsbad, CA. IMR90 primary human lung fibroblast cells were grown in Minimum Essential Media (MEM) supplemented with Earle's salt, 10% Fetal Bovine Serum (FBS) and 1-mM Sodium Pyruvate. HEK293 cells and NIH3T3 cells were each grown in Dulbecco's modified Eagle's medium supplemented with 10% FBS. Both were grown in 37°C incubator with 5% CO2.
Transfections used Lipofectamine 2000 (Life Technologies), preparing it with the DNA in Optimem (Life Technologies) per manufacturer's recommendations. The DNA–lipofectamine complexes were added to cells resuspended in growth media before plating. Transfected cells were placed back in the incubator for 3–5 h after transfection before any further treatment.
Sendai Virus (SeV) (Charles River Laboratories), was centrifuged to clarify the virus and stored at –80°C. For virus infections, we used 50 μl of virus per 1 ml of culture media. Interferon-β (Peprotech, catalog # 300–02BC) was used at 0.1 ng of IFN-β per 1 ml of culture media. These treatments were for 6 h, except for the Luciferase assays, which were for 24 h before prepping the cells for the assay.