Mononuclear cell isolation from blood samples
Blood samples were collected into anticoagulated tubes. Mononuclear cells were isolated by density centrifugation using Lymphoprep (Stemcell Technologies, Seattle, WA, USA). PBMCs were washed with RPMI-1640 medium (Sigma-Aldrich, St. Louis, MO, USA) and used either directly or cryopreserved in fetal bovine serum containing 10% DMSO (Sigma-Aldrich). After thawing, cells were washed with RPMI and re-suspended in enriched media.