Percentage of CD4
T cells expressing interleukin-2 (IL-2). The upper panels show the percentage (mean ± standard deviation) of CD4+ and CD8+ T cells, distributed among their functional compartments, producing IL-2 (within the correspondent functional compartment of CD4+ or CD8+ T cells, respectively) and amount of protein expressed per cell, measured as mean fluorescence intensity (MFI) (mean ± standard deviation), after mononuclear cell (MNC) stimulation with phorbol myristate acetate (PMA) plus ionomycin in the absence of mesenchymal stromal cells (MSCs) (MNCs + PMA + ionomycin) or in co-culture with MSCs (MSCs + MNCs + PMA + ionomycin). The lower panel represents the percentage of inhibition induced by MSCs on the percentage of CD4+ and CD8+ T cells expressing IL-2. Statistically significant differences were considered when P <0.05 for Wilcoxon paired-sample test: *versus MSCs + MNCs + PMA + ionomycin; **P <0.05 for the groups indicated in the figure. CM, central memory; EM, effector memory.