CD161 triggers CXCL8 release, but not cytotoxicity in UCB-derived NK cells. (A) Purified CD161⁺CD56⁺LFA-1⁻ immNK and PB NK cells were incubated in GAM-coated plates in the presence of RPMI+15% serum (medium), cytokine-mix, anti-CD161 and anti-NKp44 mAbs. After 24 hours, supernatants were collected and analyzed for the presence of CXCL8 (dark gray bars) and IFN-γ (light gray bars) by ELISA multiplex assay. Data are expressed as mean (± SEM) of pg/mL obtained in 3 independent experiments. (B) UCB-derived NK cells and PB-mature NK cells were analyzed for CD107a expression in a 3-hour redirected killing assay against the FcγR⁺ P815 murine mastocytoma cell line. The E/T ratio was 2/1 and was calculated on the percentages of NK cells present in each culture. Top dot plots shows the analyses of CD107a expression in UCB derived CD56⁺LFA-1⁺ difNK cells and CD56⁺LFA-1⁻ immNK cells. Bottom dot plots represent CD107a expression in PB-derived NK cells. Representative experiments of 5 performed.