(a)
(b)
(c)
Figure 5: NKG2DL and HLA I expression importantly influence NK cell activation. (a) NKG2DL expression was measured semiquantitatively by calculating the MFIR (Mean Fluorescence Intensity Ratio). The blasts were grouped by the mean MFIR of ULBP1-4 into and blasts (mean MFIR 6.6; , ). blasts were lysed by trend higher than blasts including the E : T ratio 10 : 1 of two healthy volunteer donors by immunomagnetic CD56+ enriched and CD3+ depleted NK cells (, ; ). (b) The blasts were grouped by HLA I expression. HLA blasts were defined by HLA I molecules per cell within the range of the mean and standard deviation (SD) or higher; the HLA blasts were below the mean minus SD. The NKG2DL expression significantly correlated to NK cell mediated cytolysis of two healthy volunteer donors in the HLA blast group at E : T ratio 10 : 1 (, Pearson ; ). (c) blasts showed a significant inverse correlation of HLA I molecule expression per cell and NK cell mediated cytolysis of two healthy volunteer donors at E : T ratio 10 : 1 (, Pearson ; ).