The Notch ligands Jagged2 Delta1 and Delta4 induce differentiation and expansion of functional human NK cells from CD34+ cord blood hematopoietic progenitor cells

摘要

Notch receptor signaling is required for T cell development, but its role in NK cell development is poorly understood. We compared the ability of the five mammalian Notch ligands (Jagged1, Jagged2, Delta1, Delta3, or Delta4) to induce NK cell development from human hematopoietic progenitor cells (HPCs). CD34+ HPCs were cultured with OP9 stromal cell lines transduced with one of the Notch ligands or with OP9 stromal cells alone, in the presence of IL-7, Flt3L, and IL-15. Differentiation and expansion of CD56+CD3− cells was greatly accelerated in the presence of Jagged2, Delta-1, or Delta-4, versus culture in the absence of ligand or in the presence of Jagged1 or Delta3. At four weeks, cultures containing Jagged2, Delta1, or Delta4 contained 80–90% NK cells, with the remaining cells being CD33+ myeloid cells. Notch-induced NK (N-NK) cells resembled CD56^bright NK cells in that they were CD16-, CD94−, CD117+, and KIR-. They also expressed NKp30, NKp44, NKp46, 2B4, and DNAM-1, with partial expression of NKG2D. The N-NK cells displayed cytotoxic activity against the K562 and RPMI-8226 cell lines, at levels similar to activated peripheral blood NK cells, although killing of Daudi cells was not present. N-NK cells were also capable of IFN-γ secretion. Thus, Notch ligands have differential ability to induce and expand immature but functional NK cells from CD34+ HPCs. The use of Notch ligands to generate functional NK cells in vitro may be significant for cellular therapy purposes.