Kyoizumi Seishi, Kubo Yoshiko, Kajimura Junko, Yoshida Kengo, Hayashi Tomonori, Nakachi Kei, Moore Malcolm A, van den Brink Marcel R M, Kusunoki Yoichiro
Department of Molecular Biosciences, Radiation Effects Research Foundation, Hiroshima 732-0815, Japan;
Department of Molecular Biosciences, Radiation Effects Research Foundation, Hiroshima 732-0815, Japan.
J Immunol. 2017 Oct 15;199(8):2777-2793. doi: 10.4049/jimmunol.1601711. Epub 2017 Sep 11.
The role of Notch signaling in human innate lymphoid cell (ILC) differentiation is unclear, although IL-7 and IL-15 promote differentiation of natural cytotoxicity receptor (NCR) NKp44 group 3 ILCs (NCRILC3s) and conventional NK (cNK) cells from CD34 hematopoietic progenitor cells (HPCs) ex vivo. In this study, we analyzed the functions of Notch in the differentiation of NCRILC3s and cNK cells from human HPC subpopulations circulating in peripheral blood by limiting dilution and clonal assays using high-throughput flow cytometry. We demonstrated that Notch signaling in combination with IL-7 induced NCRILC3 differentiation, but conversely suppressed IL-15-dependent cNK cell generation in CD45RAFlt-3c-Kit, a novel innate lymphocyte-committed HPC subpopulation. In contrast, Notch signaling induced CD45RAFlt-3c-Kit multipotent HPCs to generate CD34CD7CD62L, the earliest thymic progenitor-like cells, which preserved high cNK/T cell potential, but lost NCRILC3 potential. These findings implicate the countervailing functions of Notch signaling in the fate decision between NCRILC3 and cNK cell lineages at different maturational stages of human HPCs. Inhibition of Notch functions by Abs specific for either the Notch1 or Notch2 negative regulatory region suggested that both Notch1 and Notch2 signals were involved in the fate decision of innate lymphocyte-committed HPCs and in the generation of earliest thymic progenitor-like cells from multipotent HPCs. Furthermore, the synergistic interaction between Notch and IL-7 in NCRILC3 commitment was primarily explicable by the induction of IL-7 receptor expression in the innate lymphocyte-committed HPCs by Notch stimulation, suggesting the pivotal role of Notch in the transcriptional control required for human NCRILC3 commitment.
尽管白细胞介素-7（IL-7）和白细胞介素-15（IL-15）可在体外促进自然细胞毒性受体（NCR）NKp44⁺ 第3组固有淋巴细胞（NCRILC3s）和常规自然杀伤（cNK）细胞从CD34⁺ 造血祖细胞（HPCs）分化而来，但Notch信号通路在人类固有淋巴细胞分化中的作用尚不清楚。在本研究中，我们通过有限稀释法和使用高通量流式细胞术的克隆分析，分析了Notch在外周血中循环的人类HPC亚群分化为NCRILC3s和cNK细胞过程中的功能。我们证明，Notch信号通路与IL-7联合可诱导NCRILC3分化，但相反地，在一种新的固有淋巴细胞定向HPC亚群CD45RA⁺Flt-3⁻c-Kit⁺中，Notch信号通路会抑制IL-15依赖的cNK细胞生成。相反，Notch信号通路诱导CD45RA⁺Flt-3⁻c-Kit⁺多能HPCs生成CD34⁺CD7⁺CD62L⁺，即最早的胸腺祖细胞样细胞，这些细胞保留了高cNK/T细胞潜能，但失去了NCRILC3潜能。这些发现表明，在人类HPCs不同成熟阶段，Notch信号通路在NCRILC3和cNK细胞谱系的命运决定中具有相反的功能。用针对Notch1或Notch2负调控区的抗体抑制Notch功能表明，Notch1和Notch2信号均参与固有淋巴细胞定向HPCs的命运决定以及多能HPCs生成最早的胸腺祖细胞样细胞的过程。此外，Notch与IL-7在NCRILC3定向中的协同相互作用主要可通过Notch刺激诱导固有淋巴细胞定向HPCs中IL-7受体表达来解释，这表明Notch在人类NCRILC3定向所需的转录控制中起关键作用。
