sIL-6R，IL-6和SCF对人脐血CD34^＋细胞的扩增作用

1995年,我们发现由于细胞因子(SCF)和白细胞介素6(IL-6)/可溶性白细胞介素6受体(sIL-6R)复合物同时激活c-kit和gp130信号系统,有利于CD34~ 细胞的扩增。在此基础上,我们进一步研究了同时激活这两个信号系统对更原始的脐血长期培养启动细胞(long-term culture-initiating cell,LTC-IC)和混合造血细胞集落形成单位(CFU-Mix)的扩增作用。

Effects of sIL-6R, IL-6 and SCF on Expansion of CD34~ Cell from Human Umbilical Cord Blood

The object of this study was to elucidate the effect of coactivating signals through gpl30 and c-kit on the expansion of cord blood hematopoietic stem/progenitor cells. CD34 cells were isolated from human umbilical cord blood by Dynal beads M-450 CD34 im-munoselection system and expanded with different cytokines or cytokine combinations including SCF, IL-6, sIL-6R and IL-3 in a 21-day suspension culture system. The expansion efficiency of CFU-Mix and LTC-IC by methylcellulose culture and limiting dilution assay was studied, respectively. A combination of SCF, IL-6 and sIL-6R, but not SCF, IL-6 or sIL-6R alone, produced dramatic increase in the population of various cell lineages. The highest expansion efficiency in the combination of SCF, IL-6 and sIL-6R was found during 7 - 14 days after culture, and CFU-Mix and LTC-IC increased 22.5 - and 3.5- fold, respectively, while CD34 cells treated with combination of SCF, IL-6 and IL-3 after two weeks CFU-Mix only increased 13. 0 - fold and LTC-IC 1.9- fold. These results suggested that gp130 signaling in association with c-kit activation may provide a novel approach for ex vivo expansion of human primitive hematopoietic progenitors.