Transcriptional changes in IL-2, IL-12 and IL-18 stimulated human natural killer cells

We used Affymetrix expression arrays to determine changes in gene expression associated with activation of human NK cells mediated through treatment with cytokines IL-2, IL-12 and IL-18 over a 24 hour period. Human natural killer cells were isolated via negative selection from PBMCs of healthy donors. Cells were found to be > 95% CD3-CD56+. RNA was harvested at time of isolation or after 24 hour stimulation from 8 x 10^6 cells per condition. For stimulations, cells were incubated at 37C (5% CO2) in RPMI, suuplemented with 10% Fetal Bovine Serum at 1.5 x 10^6 cells/ml. Cytokine stimualtions were conducted with IL-2 (100U/mL), IL-12 (10ng/mL) and IL-18 (100ng/mL) from 2 male donors (N = 4). Expression analysis was carried out to determine transcriptional changes associated with 24 hr stimulation relative to freshly isolated cells.