Fig. 1

Effect of DPMSCs on NK cell proliferation. a Proliferation of natural killer (NK) cells was significantly increased in the presence of decidua parietalis mesenchymal stem/stromal cells (DPMSCs) as compared with untreated resting unactivated NK cells. b The proliferative response of NK cells in the presence of DPMSCs increased only at 2.5:1 and 1:1 NK:DPMSC ratios as compared with untreated IL-2-activated NK cells. Results of 10 representative experiments in which the proliferation of resting unactivated or IL-2-activated NK cells cultured for 72 h with or without mitomycin C-treated DPMSCs at different ratios of NK:DPMSC (10:1, 7.5:1, 5:1, 2.5:1, and 1:1) in the presence of 100 U/mL IL-2 was measured using MTS proliferation method. Experiments were carried out in triplicate and repeated 10 times using NK cells and DPMSCs prepared from the peripheral blood of 10 different healthy donors and 10 different fetal membranes, respectively. Bars represent standard errors. *P < 0.05