Expression of functional EpoR in human T cells. (A) Flow cytometric dot-plots illustrate surface EpoR expression in Jurkat cells, as detected by a PE-conjugated anti-EpoR antibody (R&D Systems); cells transduced with GFP only are shown as control. Percentage of cells in each quadrant is shown. (B) Flow cytometric histogram illustrates Epo binding to Jurkat cells. Cells were labeled with biotin-conjugated Epo (R&D Systems) and streptavidin-PE (Jackson ImmunoResearch Laboratories). (C) Surface EpoR expression in T lymphocytes transduced with GFP only or GFP plus EpoR. (D) Representative flow cytometric dot plots illustrate phosphorylation of STAT5 Y694, detected with an AF647-conjugated antibody (BD Biosciences) after stimulation with 10 IU/mL Epo for 15 minutes; results with cells treated with 10 µM ruxolitinib for 1 hour before Epo stimulation are also shown. (E) Survival of EpoR-transduced T cells and of T cells transduced with GFP only cultured in absence of exogenous cytokines (no Epo) or in presence of Epo (4 IU/mL). Symbols indicate percentage of cell recovery relative to the number of input cells.