Fig. 3.

Memory-like NK cells lack granzyme B protein and kill target cells similar to control NK cells. (A) Preactivated, memory-like NK cells (solid black line) do not express granzyme B protein 7 days after adoptive transfer into Rag1^−/− hosts as compared with a positive control, NK cells activated with high-dose (100 ng/mL) IL-15 for 2 days. (Dashed line, control-treated NK cells; shaded, negative control; gray line, positive control). (B) Donor and host NK cells were sorted from recipients that had received activated or control NK cells 7 days prior and were used as effectors in a cytotoxicity assay with Yac-1 targets at the indicated effector to target (E:T) ratios. Data represent the mean of duplicate wells and results are representative of 2 independent experiments.