Delta-1对IL-6R^+髓系祖细胞分化的影响

Influence of Delta-1 on the differentiation of interleukin 6 receptor-positive myeloid progenitors in human

目的探讨Notch配体Delta-1在髓系造血细胞分化过程中对膜结合和可溶性IL-6受体所介导信号的调节作用。方法分离正常脐血单核细胞,然后利用CD34免疫磁珠试剂盒和FACSVantage流式细胞仪从所获单核细胞中拣选CD34+CD38-细胞;将CD34+CD38-细胞利用SCF、Flt3L、TPO和IL-3(4GFs)培养7 d,用CD36免疫磁珠试剂盒分离掉培养细胞中的CD36+红系祖细胞,然后用FACSVantage流式细胞仪将细胞再次拣选出CD15-CD14-CD1a-IL-6R+表型的细胞,将这种表型的细胞用含有4GFs、4GFs+IL-6或4GFs+FP6培养基在有或无Delta-1存在的条件下进行培养11 d,并对CD15+粒细胞、CD14+单核细胞和CD14-CD1a+树突状细胞进行计数。结果发现所有CD15、CD14或CD1a阳性的细胞均表达IL-6R;IL-6和FP6可促进CD15+细胞的分化;Delta-1在无IL-6和FP6存在时对CD15+细胞的分化表现出轻度的抑制作用;在IL-6和FP6存在时对CD15+粒细胞的分化表现出明显的抑制作用;相反,IL-6和FP6抑制CD14-CD1a+细胞的分化,而Delta-1促进CD14-CD1a+细胞的分化。结论Delta-1可通过抑制mIL-6R-和sIL-6R所介导的IL-6生物学效应抑制IL-6R+髓系祖细胞分化为粒细胞和单核细胞,但促进其分化为树突状细胞。

Objective To elucidate the regulatory role of Notch signaling in the mIL-6R and sIL-6R mediated IL-6 signaling pathway. Methods Mononuclear cells were isolated from the normal cord blood samples by Ficoll solution, and then enriched for CD34 ^＋ CD38^- cells by using CD34 immunomagnetic beads and a FACSVantage. CD34^＋ CD38^- cells were cultured for 7 days in the presence of SCF, Flt3L, TPO, and IL-3 （4GFs）, and depleted of CD36 ^＋ erythroid progenitor using CD36 immunomagnetic heads, and then sorted for cells with the phenotype of CD15^- CD14^- CD1a^- IL-6R^＋ using the FACSVantage. Furthermore, the CD15^- CD14^- CD1a^- IL-6R^＋ cells were cultured in the medium containing 4GFs, 4GFs ＋ IL-6, or 4GFs ＋ FP6 in presence or absence of Deha^-1 for 11 days and cell count was conducted for CD15 ^＋ granulocytic, CD14^＋ monocytic, and CD14^- CD1a^＋ cells. Results IL-6R was expressed in all CD15^- , CD14^- , or CD1a^-positive cells. IL-6 and FP6 could enhance the generation of CD15^＋ cells. Delta^-1 had a mild inhibitory effect on the generation of CD15^＋ cells in the absence of IL- 6 and FP6, but a strong inhibitory effect in the presence of IL-6 and FP6. Conversely, the generation of CD14^- CD1a^＋ cells was suppressed by IL-6 and FP6 but enhanced by Delta^-1. Conclusion Delta^-1 can promote the differentiation of IL-6R^＋ myeloid progenitors into CD14^- CDIa^＋ dendritic cells but inhibit differentiation of ID6R^＋ myeloid progenitors into CD15^＋ granulocytic and monocytic cells via repressing mIL-6R- and sIL-6R-mediated signaling pathway.