In vitro purification and stimulation of pDC
pDC was purified using CD304 microbeads (130-090-532, Miltenyi Biotec) and maintained in RPMI 1640 supplemented with 10% fetal bovine serum (FBS) (Gibco, USA), 100 U/ml penicillin and 100 μg/ml streptomycin (15140122, ThermoFisher). For cytokines detection, PBMCs were stimulated with 5 μg/ml R848 (tlrl-r848, InvivoGen) or 10 μg/ml ODN-2216 (tlrl-2216, InvivoGen) in the presence of 100 ng/ml IL-3 (Peprotech, 200-03). R848 is a ligand for Toll-like receptor 7 (TLR7) and OND-2216 is a ligand for TLR9.