FIG. 4.
Inhibition of AA-induced antiviral activity by anti-IFN-α/β serum. PM (106/well) were seeded in 24-well cluster plates as described in Materials and Methods. After a 24-h incubation and a vigorous washing, PM cultures were infected with EMCV at an MOI of 1. After viral adsorption, incubation proceeded for 48 h in the presence of 1,000 μM AA and 4,000 neutralizing units of anti-IFN-α/β serum or 600 neutralizing units of anti-IFN-γ serum. Virus yields were then determined as described in Materials and Methods. Values represent a mean of three different experiments, and each experiment contained duplicate samples per condition. Statistical analysis by Kruskall-Wallis test gave the following results: AA versus control, P < 0.004; AA + antibody to IFN-α/β versus AA, P < 0.004.