Fig. 2

Evolution of cytotoxic scores along the time in each recipient group comparing different types of target cells. Mean ± S.E.M. of cytotoxic scores (Y axis) assigned to neat sera (top row; a, b, c), 1:2 diluted sera (middle row; d, e, f), and 1:16 diluted sera (bottom row; g, h, i) from mismatched recipients of MSC-naïve (left column; a, d, g) and MSC-primed, halfmatched (middle column; b, e, h) and mismatched (right column; c, f, i), along the time (X axis; T0, pre-administration of corresponding MSCs; T1, 1 week after first MSC administration; T2, 3 weeks after first MSC administration—just before the second MSC administration; T3, 1 week after second MSC administration; T4, 90 days after second MSC administration), when assayed against different target cells: PBLs, peripheral blood lymphocytes (white bar, control); MSC-naïve, unstimulated mesenchymal stem cells (light gray bar); MSC-primed, mesenchymal stem cells pre-stimulated with tumor necrosis factor alpha and interferon gamma (dark gray bar). Asterisks (*) point out statistically significant differences among time-points (* = p < 0.05, ** = p < 0.01, *** = p < 0.001) and hashes (#) indicate significant differences between different target cells at one particular time (# = p < 0.05, ## = p < 0.01)