KIR2DL2/L3/S2 is preferentially expressed on NK cells derived from single UBC progenitors.

Single UCB CD34⁺/Lin⁻/CD38⁻cells were cultured on AFT024 and IL-7 (n = 4 UCB donors), IL-7 + IL-15 (n = 10 UCB donors), and IL-7 + IL-2 (n = 11 UCB donors) for 26 to 36 days. The number of replicate single cell progeny analyzed for each condition is listed as the n value above each bar. Progeny of each single cell was split into 3 or 4 aliquots for immunophenotyping. (A) The absolute number of NK cells derived from a single cell was greatest for IL-2 compared with IL-15 (P < .0001). There was no difference in CD94 expression at this early time point. ▪, CD56⁺, and ▨, CD94⁺ NK cells. (B) The absolute number of NK cells expressing individual KIR was evaluated. For IL-15– and IL-2–containing cultures, GL183 was expressed greater than EB6 (P = .03 and P = .004, respectively) or DX9 (P = .014 and P = .005, respectively) staining cells. ░, KIR3DL1; ▨, KIR2DL1/S1; ▪, KIR2DL2/L3/S2. (C) Single CD34⁺/Lin⁻/CD38⁻ cells were sorted from fetal liver (n = 2), UCB (n = 4), and adult BM (n = 3) on AFT024 with FL, KL, IL-3, IL-7, and IL-2. After 40 to 55 days, replicates from each stem cell source were harvested, split, and stained for each of the individual KIR antibodies as indicated. AllP values listed are for significant differences compared with fetal liver–derived NK cells. Compared with other KIRs, KIR2DL2/L3/S2 expression was significantly greater for fetal liver (P = .003 compared with KIR2DL1/S1; P = .003 compared with KIR3DL1) and UCB (P = .005 compared with KIR2DL1/S1; P = .003 compared with KIR3DL1). ▪, fetal liver (n = 26); ▨, cord blood (n = 69); ■, adult marrow (n = 59).