Skip to main content
. 2021 Mar 18;12:610789. doi: 10.3389/fimmu.2021.610789

Figure 2.

Figure 2

NK cell commitment is represented by the transition from CLPs to NKPs that acquire the most representative hallmark CD122. With the expression of NK1.1 and NKp46, immature NK (iNK) cells are originated from NKPs. According to the expression of CD27 and CD11b, NK cell maturation can be distinguished into four stages: CD11b−CD27−(iNK) → CD11b−CD27+(M1) → CD11b+CD27+(M2) → CD11b+CD27−(M3). Stromal cells expressing IL-15α are sufficient for the generation of immature NK cells in the BM. Moreover, some unrecognized hematopoietic cells contribute to differentiate into M1 and M2 NK cells by supplying IL-15. After migration from BM to the periphery, DCs and macrophages transpresent IL-15 for M2 to promote NK cell terminal maturation. Both hematopoietic and non-hematopoietic cells promote NK cell development by producing IL-15 at different stages.