Killing activity from mutant NK cells is intact. (A-B) Killing activity of d5-activated NK cells was assessed in a 35S release assay against YAC-1 and RMA-RAE ε target cells at different effector/target ratios. (C) Killing activities of d5-sorted NK cells against RMA, RMA-S, and B16-F10 targets (E/T ratio = 10/1). Results (mean ± SD) are representative of 2 to 3 independent experiments. (D) Percentages of CD107a+ NK cells upon 5-hour incubation with YAC-1 (upper panel) and RMA and RMA-S cells (lower panel). Results are representative of 2 independent experiments. (E) Representative FACS histograms depicting Helios expression in CD11b+ NK cells from splenocytes of each genotype. Helios staining corresponds to the plain lines, whereas isotype control is depicted as the shaded histograms (upper panel). The mean fluorescence intensity of intracellular Helios staining among CD11b+ and CD11b– NK cells is shown in the lower panel (n = 3-5 mice/genotype). The data are representative of 3 experiments.
