Figure 1. Regulation of Notch expression and signaling on NK cells.

A) Pooled umbilical cord blood (UCB, n=5) was used as a source of hematopoietic progenitors and Notch-1 transcript expression (normalized to GAPDH) was determined at different stages of NK cell development (Stage 1-CD34⁺CD117⁻CD56⁻, Stage 2-CD34⁺CD117⁺CD56⁻, Stage 3-CD34⁻CD117⁺CD56⁻CD94/CD16⁻, and Stage 4/5-CD34⁻CD117⁻CD56⁺CD94/CD16⁺). (B) Peripheral blood NK cells were first enriched utilizing magnetic beads and then sorted based on CD56 expression and presence of KIR. Notch-1 transcript expression (normalized to GAPDH) was determined in CD56^brightKIR⁻, CD56^dimKIR⁻, and CD56^dimKIR⁺ NK cells (n = 4). (C) Representative Western Blot of full length (FL) and intercellular Notch-1 (ICN) protein in enriched adult NK cells after overnight culture with no cytokine or 10 ng/ml of IL-15 in the presence of either DMSO or 20 µM γ-secretase inhibitor (gSI) (n = 6). (D) c-Myc transcript expression (normalized to 18s) in adult NK cells after 3 days of stimulation with 10 ng/ml of IL-15 in the presence of either DMSO or 20 µM gSI (n=6).