IL-22 producing NKp46+ innate lymphoid cells can differentiate from hematopoietic precursor cells.

The IL-22 NKp46(+) innate lymphoid cells, NCR22 cells, are very important for the early host defense against microbial pathogens. We show here that NCR22 cells were differentiated from Lin(-)CD127(+)CD117(+) cells that were derived from hematopoietic precursor cells (HPCs) of mouse bone marrow cells. The combination of low concentrations of IL-23 and IL-15 induced differentiation of NCR22 cells from Lin(-)CD127(+)CD117(+) cells. NCR22 cells expressed a large amount of IL-22 and RORγt, and they had poor cytolytic activity and produced little IFN-γ. Lin(-)CD127(+)CD117(+) cells were very similar to intestinal lamina propria LTi-like cells; both cells dominantly expressed RORγt and IL-22. Meanwhile, Lin(-)CD127(-)CD117(+) cells that were also derived from HPCs did not express RORγt and IL-22, and they developed into conventional NK cells, not into NCR22 cells. These findings revealed that NCR22 cells can be differentiated from Lin(-)CD127(+)CD117(+) cells which are derived from HPCs.