Immune complexes-induced pDC activation is complement independent. IFN-α responses of enriched pDC (CD14-depletion/CD172a-enrichment) stimulated by FMDV O UKG 2001 (MOI of 1 TCID50/cell) pre-incubated with serum from a naïve and O Manisa-immune pig. The serum was either untreated (A) or heat-treated at 56°C for 30 min (B). After 24 h, IFN-α in the supernatants was measured by ELISA. The mean value and the standard deviations of triplicates cultures are shown. The data are representative of three independent experiments.