FIG. 2.
hASCs induce a low degranulation in IL-2-expanded NK cells. Allogeneic PBMCs cells were prestimulated for 5 days with rhIL-2 and then sorted on the basis of CD56+CD3- phenotype. To quantify cytotoxic granule exocytosis, the surface expression of CD107a/b was analyzed after activation of purified NK cells co-cultured with target cells (hASCs, hBM-MSCs, K562, or none) at a 1:1 (NK:Target) ratio. Graph A represents mean and SD of the percentage of CD107a/b on CD56 positive cells in 5 different experiments. A representative dot plot of each condition is shown in B. The numbers within the quadrants represent the percentage of CD107a/b in purified NK cells. *Significant at P≤0.05. PBMC, peripheral blood mononuclear cell; IL-2, interleukin 2.