Monocytes, pDCs, B cells and circulating CD11c + DCs (cDCs) were isolated from blood of healthy donors (New York Blood Center) using Miltenyi isolation kits. CD14 + clinimacs, for monocytes, CD123/BDCA4 kit for pDCs and BDCA1 kit for cDCs. B cells were isolated as part of the BDCA1 kit for isolation of cDCs according to manufacturers' instructions. The purity of each cell population was tested by flow cytometry as described below and was routinely 85-95% for CD14 + cells, 87-90% for pDCs, and 95-99% for both MDDCs and cDCs.