Fig. 4

The potential of allogeneic stem cells to overcome immune barriers correlates with their ability to suppress virus-induced T, NK and NKT-like cell responses. a Allogeneic RM35 ADSC suppress vaccinia virus-induced innate and adaptive immune responses. 250 k PBMCs from 2 different blood donors (RM047 and RM048) were cocultured with 0.4–60 k allogeneic RM35 ADSC for 48 h in the presence or absence of 10 k pfu of WT1 VV. The figure shows a representative flow cytometry analysis of gated live T, NK, and NKT-like cells (see Additional file 4: Figure S4A) from blood donor RM048 at the highest 60 k ADSC dose. b Summary of the modulation of anti-viral responses by the RM35 ADSC in the PBMC donors RM047 and RM048 as in a. Bars show the percentage of CD69+ activated cells from each immune cell type as indicated. A brief 4 h stimulation with 250 k K562 cells at the end of the 48 h coculture period was used to evaluate the immunosuppressive potential of the allogeneic stem cells against NK cells. Bars represent duplicate measurements ± SD. Statistically significant differences (Student T-test, p < 0.05) versus the corresponding PBMC alone controls (CTRL) or as indicated are marked with asterisks. In the K562 groups asterisks indicate statistically significant difference versus the corresponding K562 CTRL, which represents PBMC cocultured alone without ADSC, with or without virus (solid versus empty bars, respectively)