Fig. 5
UM171a instills antigen cross-presentation properties without PD-L1 induction on the surface of MSCs. A Representative flow-cytometry analysis of H2-Kb on MSCs treated with IFN-gamma or UM171a. The dashed line represents the basal expression level of H2-Kb before treatments. B An antigen cross-presentation experiment comparing MSCs treated with UM171a versus IFN-gamma. OVA pulsing was conducting for both 8 or 18 h. C Representative flow-cytometry experiment assessing the expression of PD-L1 on both UM171a- or IFN-gamma-treated MSCs. The small integrated histogram represents PD-1 expression (in orange) on the B3Z cell line. D IDO-1 quantification by MSCs treated for 72 h with DMSO or UM171a versus 12 h with IFN-gamma (10 ng/ml). E, F IFN-gamma and IL-2 quantification by OT-I CD8 T cells in response to UM171a- or IFN-gamma-treated MSCs. The PD-L1 neutralizing antibodies were used at 0.5 μg/ml. For panels B, D, E, and F, n = 5/group with *P < 0.05 and ***P < 0.001