pDCs but not cDCs exposed to a low dose of IFN-β prior to TLR ligand activation demonstrate DC activation priming.

cDCs and pDCs were pretreated with IFN-β (50 units/ml) 3 hours prior to treatment with live influenza PR8 virus, or UV-inactivated influenza, or LPS, or CpG, or poly (I∶C), or CL-075 Gardiquimod (Gard). The robustness of priming is given as the fold increase of mRNA expression of IFN+TLR ligand over the amount of expression from the IFN alone sample and TLR alone samples [IFN+TLR ligand sample / (IFN alone sample+TLR alone sample)]. Data are representative of at least two independent experiments in which both dose and time courses of activation were done. n/d signifies not determined.