Dose-dependent reduction in viable cells with type-I IFNs.

(A) Coculture with type-I IFNs reduced cell recovery of monocyte-derived DC. Relative viable cell recovery of DC at day 10 of culture is presented. Type-I IFNs were added at days 1 and 4 of culture at the indicated concentrations. n = number of independent experiments; *P < .05, **P << .01 as determined by pairedt test. (B) IFN-β induced a small but significant decrease in cell viability after 10 days of culture. On day 10 of culture, cells were harvested and subjected to flow cytometric analysis to evaluate the percentage of dead cells with propidium iodide (PI) staining. Numbers indicate the percentage of PI-positive cells. Results are 2 representatives of 5 independent experiments.