Isolation and Characterization of PBMCs

Blood samples were collected in sodium-heparin tubes (Greiner Bio-One, Germany) followed by isolation of peripheral blood mononuclear cells (PBMCs) as described before [19 (link)]. PBMCs were thawed, centrifuged for 5 min (1500 rpm, 4 °C) and resuspended in 100 μl sort‐buffer (PBS pH 7.4, 2 mM EDTA 1 M, 0.5% BSA). For membrane staining, cells were incubated for 15 min in the dark with anti‐CD14 (APC/Cy7; Becton Dickinson Biosciences, San Diego, USA), anti-BDCA‐4 (PE; Miltenyi Biotec, Bergisch Gladbach, Germany), anti‐CD123 (PE-Cy7; eBioscience, San Diego, USA), anti‐CD3 (PerCP-Cy5; Becton Dickinson Biosciences), and anti‐CD19 (APC; Becton Dickinson Biosciences). Cells were sorted using a FACSAria III cell sorter (BD Bioscience) and analyzed using FlowJo Sofware (TreeStar Inc., Ashland, USA).