Up-regulation of IL-2/15Rβ (CD122) on naive CD8⁺T cells and of IL-2/15 Rγ (CD132) on all subsets after IL-15 stimulation. The purified subsets were labeled with CFSE and stimulated with IL-15 (10 ng/mL) for 7 days. NK cells gated on CD3-CD16+CD56+ (NK), CD8+ T cells purified from UCB (UCB CD8⁺), peripheral naive CD8⁺ T cells (CD27⁺CD45R^Abright), cytotoxic CD8⁺ T cells (CD27^-CD45RA^bright), and noncytotoxic CD8⁺ T cells (CD27⁺CD45RA^dull/neg) were stained for CD122 (IL-2/15 Rβ), CD132 (IL-2/15 Rγ), and IL-15Rα followed by FACS analysis. Dashed line indicates isotype control; thin line, resting cells; and bold line, IL-15-stimulated cells. Data are one representative experiment of 3 performed.