Fig 1: Type I IFNs are responsible for the priming of DCs to produce IL-12p70. MDDCs were incubated with different concentrations of recombinant human IFN-α 4 h prior to infection with SP. The cells were further incubated for 18 h before the concentration of IL-12p70 in the supernatants was measured by ELISA.MDDCs were sequentially infected with IAV and SP in the presence of neutralizing antibodies against IFN-α, IFN-β and IFNAR. After 22 h incubation the cells were lysed and total RNA was isolated and assayed for the presence of IL-12p35 and IL-12p40 mRNA. Ct values were normalized against γ-actin and the relative induction of the genes was calculated using the ΔΔCt method.Values represent mean ± SEM three independent experiments with different donors (A) or one representative donor of 3 (B, C). Statistical analysis was performed using paired Student’s t-test. (*P < 0.05).