Figure 6.

Cytotoxicity of NKG2C+ NK cells towards primary HLA-E+/HLA-G+ glioblastoma cells. (a) Flow cytometry analysis of HLA class I as well as of HLA-E and HLA-G surface expression in HT7606, HT18584 and HT18816 primary glioblastoma cells. As indicated, all GBM cells express HLA class I molecules and are positive for HLA-E and HLA-G. Isotype staining controls are included (grey histograms). (b) Chromium release assay demonstrating preferential killing of HLA class I-positive glioblastoma cells by NKG2C+ NK cells from two donors at indicated target to effector ratios when compared to NKG2A+ NK cells and fresh NK cells. Potential alloreactivity (i.e., missing HLA self-ligand for KIR) is depicted in inlets. ** p < 0.01.