These CD8+T cells were subsequently CFSE-stained and cultured on plates coated with anti-CD3 (0.005 μg/ml) in combination with anti-CD28 (0.5 μg/ml) as a positive control or anti-NKG2D (0.5 μg/ml). Proliferation was measured after 60 h by flow cytometry. Untreated CFSE-stained CD8+T cells are included for comparison. The percentage of proliferating cells and the MFI for CFSE are indicated.The MFI of CFSE in unstimulated CD8+T cells (control) was set to 100% in individual experiments (n = 6), and the relative decrease due to proliferation was calculated. Means + SD are shown. Significant differences (Wilcoxon test) between CD8+T cells pre-exposed to anti-NKG2D and isotype control (mIgG1) were found in these experiments at anti-CD3 concentrations of 0.01 and 0.005 μg/ml. 