FIG 2.

Neutralization of IFN-β in PI cells. Control cells or PI cells were pretreated with antibody against IFN-β at 24 h prior to infection with rNDV-GFP. Supernatants were harvested at 48 h p.i. and tested for their levels of IFN-β by ELISA (top). Titers of these supernatants were determined by plaque assay (bottom). The data shown are means of triplicates. Error bars represent standard errors of the means.