Figure 3.

Cytotoxic potency of activated primary human NK cells against acute leukemia. Killing of various leukemic cell lines by activated primary human NK cells was analyzed by co-culture of NK cells and target cells at several ratios. Activated primary human NK cells were incubated with blocking antibodies against activation receptors (as stated) and co-cultured with NOMO-1, MOLM-14, REH, THP-1, CMK, and BV-173 cells at various ratios to determine cytotoxic activity of NK cells. After 16 h of co-incubation at 37°C, the cytotoxicity of the treated and untreated NK cells was analyzed via flow cytometry, and the degree of the cell lysis was analyzed as described in the Material and Methods. The graphs represent mean ± SEM of four biological replicates.