K562 cytotoxicity assay for natural killer function
| Cultured CD56+cells . | Fresh PBMCs . | ||
|---|---|---|---|
| Ratio E/T . | Lysis (%) . | Ratio E/T . | Lysis (%) . |
| 2.5 | 6.0 ± 4.0 | 12.5 | 23.5 ± 3.5 |
| 5.0 | 18.3 ± 4.8 | 25.0 | 33.5 ± 3.5 |
| 10.0 | 25.4 ± 3.5 | 50.0 | 39.0 ± 3.0 |
| Cultured CD56+cells . | Fresh PBMCs . | ||
|---|---|---|---|
| Ratio E/T . | Lysis (%) . | Ratio E/T . | Lysis (%) . |
| 2.5 | 6.0 ± 4.0 | 12.5 | 23.5 ± 3.5 |
| 5.0 | 18.3 ± 4.8 | 25.0 | 33.5 ± 3.5 |
| 10.0 | 25.4 ± 3.5 | 50.0 | 39.0 ± 3.0 |
CD56+ cells were isolated by FACS from 2-week-old S17 cocultures in either interleukin 2 (n = 1) or interleukin 15 (n = 1). Fresh peripheral blood mononuclear cells (PBMCs) were used as a positive control (n = 2 subjects). As total fresh PBMCs were compared with CD56+-cultured cells, a higher effector-to-target (E/T) ratio was used for fresh PBMCs.