Human PBMC isolation

Whole blood was harvested from healthy human donors, and PBMCs were isolated by density gradient centrifugation using Ficoll-Paque PLUS (GE Healthcare). PBMCs were stored at −150°C in AIM V (Gibco) 10% dimethyl sulfoxide until use, with the exception of the CITE-seq experiment for which freshly harvested PBMCs were used. All research using human samples was approved by the University of Toronto Research Ethics Board (University of Toronto REB protocol no. 27673).