Interaction with Mesenchymal Stem Cells Provokes Natural Killer Cells for Enhanced IL-12/IL-18-Induced Interferon-Gamma Secretion
Figure 3
MSC promote the intracellular IFN-γ production in NK cells. NK92 cells ((a) and (b)) and primary NK- (pNK) cells ((c) and (d)) were cultured in the absence or presence of MSC at a NK : MSC ratio of 5 : 1. Cells were preincubated for 24 h prior to stimulation with IL-12 (1 ng/mL) and IL-18 (10 ng/mL). Sixteen hours after stimulation, the cells were incubated with GolgiStop for 6 h and subsequently stained with antibodies against CD56 and intracellular IFN-γ before flow cytometric analysis. ((a) and (c)) Dot plots of one representative experiment. ((b) and (d)) Bar graphs show mean values ± standard deviation of 6 (b) and 5 (d) independent experiments performed using (b) 6 different donors for MSC and (d) 3 and 4 different donors for MSC and pNK cells, respectively. Data are normalized and presented as percentage of IFN-γ positive NK cells cultured in the presence of MSC with respect to NK cells cultured alone (100%). .
