Figure 7

Degranulation assay with cytokine-differentiated NK cells. NK cell function was evaluated through flow cytometry monitoring of CD107a expression, following a previously described protocol [26]. CD34^-lineage^- cells initially differentiated with either IL-15 alone or the combination of IL-15 and IL-21 for 4 weeks were further activated for 24 hours with 100 IU/ml IL-2 (R&D Systems), followed by co-culture with NK-sensitive cells (K562) or NK-resistant cells (Raji). The different effector (E)-to-target (T) ratios indicated in the Figure were selected based on previous publications [26]. After 4 hours, cells were harvested, labeled with anti-CD107a and anti-CD56 mAb and analyzed by flow cytometry. The data shown here are representative of 4 independent experiments with similar results. The percentage of CD107a⁺CD56⁺ cells is indicated.