Fig. 5

The potential of allogeneic stem cells to function as a Trojan horse is restricted by patient-specific differences suggesting that proper matching will be required. a PBMC donors demonstrate highly variable responses to the allogeneic stem cells and the virus alone or in combination. Flow cytometry analysis of gated live NK, T, and NKT cells from 48 h cocultures of 250 k PBMCs from 4 different blood donors with 5 k-40 k allogeneic RM20 ADSC, and in the presence or absence of 5 k pfu of WT1 VV. Data show the percentage of CD69+ activated cells from each cell type. Bars represent duplicate measurements ± SD. Statistically significant differences (Student T-test, p < 0.05) versus corresponding PBMC without virus or stem cells controls (CTRL) or as indicated are marked with asterisks. b Comparison of the immunosuppressive potential of the allogenic RM20 ADSCs against the NK cells from two blood donors in which the stem cells demonstrate differential ability to “stay under the radar”. Flow cytometry analysis of cocultures of PBMC from the SIBD01 and SIBD02 blood donors as in a followed by a 4 h stimulation with K562 cells to evaluate the extent of NK cell suppression. Bars represent duplicate measurements ± SD. Statistically significant differences (Student T-test, p < 0.05) versus the corresponding PBMC alone controls (CTRL) 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). c Plaque analysis of the 48 h cocultures as in b demonstrating that RM20 ADSC can amplify WT1 vaccinia virus only in the presence of allogeneic PBMC from the permissive SIBD02 but not the resistant SIBD01 blood donor. d Correlative analysis of NK, T, and NKT cell responses (% CD69 + normalized to untreated PBMC control) against the highest dose of the allogeneic ADSCs as in (a) and (Fig. 4b). Statistically significant correlations are indicated with corresponding p values and Pearson coefficients