Peripheral blood was collected into sodium heparin tubes (BD, Cat#367874). Tubes were spun (15 min, 3000 rpm, RT), plasma removed, and banked. Remaining whole blood was diluted 1:1 with 1% RPMI (table S7) and layered into a SEPMATE tube (STEMCELL Technologies, Cat#85450) pre-loaded with lymphoprep (Alere Technologies, Cat#1114547). SEPMATE tubes were spun (10 min, 1200xg, RT) and the PBMC layer collected, washed with 1% RPMI (10 min, 1600 rpm, RT) and treated with ACK lysis buffer (5 min, ThermoFisher, Cat#A1049201). Samples were filtered with a 70 μm filter, counted, and aliquoted for staining.