NKL cell-mediated cytotoxicity assays determine the net effect of IFN-β treatment on GIC.

<p>A-E. GS-2, GS-5, GS-7, GS-8 or GS-9 cells were used as targets in cytotoxicity assays and treated with IFN-β (300 U/ml; 24 h) prior to the cytotoxicity assay with NKL cells as effectors (1 out of 2 independent experiments shown). GS-5 and GS-9 cells were additionally transfected with siRNA targeting <i>HLA-E</i> or non-targeting siRNA. Specific lysis was calculated by subtraction of background lysis. In F, HLA-E cell surface levels after HLA-E gene silencing were assessed by flow cytometry (one representative experiment shown).