FIG. 1.

IFN-β treatment suppressed both viral gene expression and infectious particle release in L929 and NIH/3T3 cells, but only partially inhibited such expression in NB41A3 cells. NB41A3, NIH/3T3, and L929 cells were treated for 24 h with a titration of IFN-β (200–1600 U/mL) or vehicle alone and infected with VSV (MOI = 3). At 6 hpi, cell supernatants and lysates were harvested. (A) Viral plaque assay. Supernatants were clarified via centrifugation at 200 RCF for 10 min, and viral titers assessed by plaque assay. Plaque assays revealed that all cell lines displayed a 10,000-fold reduction in VSV viral titers resulting from IFN-β pretreatment; error bars represent 2 × the standard deviations from experiments done in triplicate. (B) Western blot analysis. Protein concentrations from cell lysates were normalized by Lowry assay (5 μg protein per lane), resolved via 12% SDS-PAGE, transferred to nitrocellulose, and probed with anti-VSV antiserum and anti-GAPDH polyclonal antibodies. While a threefold reduction in VSV viral proteins is observed in IFN-β-pretreated NB41A3 neuroblastomas, there are undetectable levels of VSV viral proteins in IFN-β-pretreated NIH/3T3 and L929 cell lysates. Figure representative of three replicate experiments.