FIG 3.

Protective effect of exogenous IFNs on tumor and normal cells infected with rwt VSV. (a) JSQ-3 cells, (b) NHEK cells, and (c) HMVEC were preincubated for 18 h with recombinant human IFN-α2a or IFN-β at either 100 or 1,000 U/ml and then infected with rwt VSV at an MOI of 10. Viability was measured at 48 h by MTT assay. Results shown are the means ± SD from at least 3 experiments per treatment. *, P < 0.05 for 100 U/ml IFN-β versus 100 U/ml IFN-α; *, P < 0.05 1,000 U/ml IFN-β versus 1,000 U/ml IFN-α, determined by one-way ANOVA with Tukey's posttest. (d) Viral titers in supernatants from JSQ-3 cells and HMVEC cells were measured at 24 h by plaque assay. Two independent experiments for each cell type and virus are indicated by open and closed symbols.