Ex vivo studies of the immune modulation of CB-SCs on T cells. (A) Phase contrast microscopy shows the formation of cell clusters in human peripheral blood-derived lymphocytes that were activated with Dynabeads coupled with anti-CD3, anti-CD28, and anti-CD137 antibodies, 50 U/ml rIL-2, and 5 ng/ml rIL-7 for 5 days, in absence (left panel) and presence (right panel) of CB-SCs. Co-culture with lymphocytes (top right panel) served as control. Original magnification, × 100. (B) Cell proliferation was analyzed with CellTrace™ CFSE Cell Proliferation Kit. Untreated lymphocytes (left panel) served as control. (C) Multi-color flow cytometry on CD8+NKG2D+ T cells. The gated CD8+NKG2D+ T cells were further analyzed for the expression of coinhibitory molecules BTLA and PD-1. Isotype-matched IgG Abs served as control for flow cytometry. Mean fluorescence intensity (MFI) was presented for CD8+NKG2D+BTLA+PD-1+ T cells. Flow cytometry dot plots and the percentage of each population were representative of three independent experiments with similar results.