糖蛋白130和c-kit同时激活对脐血CD_(34)^+细胞的扩增作用

EXVIVO EXPANSION OF HUMAN UMBILICAL CORD BLOOD HEMATOPOIETIC CELLS BY STIMULATING gp130 AND c-kit

目的 :探讨同时激活糖蛋白 1 30 ( gp1 30 )和 c- kit信号系统 ,对脐血长期培养启动细胞 ( LTC-IC)和混合造血细胞集落形成单位 ( CFU- Mix)的扩增作用。方法 :利用免疫磁珠法分离纯化脐血 CD+ 3 4细胞 ,在体外液体培养体系中 ,经可溶性白细胞介素 6受体 ( s IL- 6R)、白细胞介素 6( IL- 6)、干细胞因子 ( SCF)和白细胞介素 3( IL- 3)的不同因子及组合扩增 3w,分别用甲基纤维素法和有限稀释法测定 CFU- Mix和 LTC- IC的扩增效率。结果 :s IL- 6、IL- 6和 SCF单独都不能使 CFU- Mix得到扩增 ,而三者联合可使 CFU- Mix数目显著扩增 ,且于培养 2 w时扩增效能最佳 ,此时 CFU- Mix扩增到 2 2 .5倍 ,LTC- IC扩增到 3.5倍 ,作为对照的 SCF+ IL- 6+ IL- 3组则仅分别扩增到 3.0和 1 .9倍。形态学分析发现 :IL- 6、s IL- 6R和 SCF协同作用下 ,产生的集落体积较大 ,并可观察到各系造血细胞集落及不同发展阶段的细胞。结论 :由 IL- 6/s IL- 6R复合物和 SCF联合激活 gp1 30和 c- kit信号系统可刺激造血干 /祖细胞发生明显扩增 ,体外扩散时间以 1～ 2周为宜。

Objective:To elucidate the effect of coactivating signals through gp130 and c kit on the expansion of cord blood hematopoietic stem/progenitor cells. Methods:CD + 34 cells were isolated from human umbilical cord blood by using a high gradient magnetic cell sorting system, expand with different cytokine or cytokine combinations 〔including stem cell factor(SCF)、interlukin(IL) 6、soluble IL 6 receptor(sIL 6R) and IL 3〕 in a 21 day suspension culture system and evaluated the expansion efficiency of culture forming unit Mix(CFU Mix) and long term culture initiating cells(LTC IC) by methylcellulose culture and limiting dilution assay respectively.Results: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 best expansion efficiency of SCF、IL 6 and sIL 6R was found during 7~14 days, when increased CFU Mix by 22.5 times and LTC IC by 3.5 times, while CD + 34 cells treated with combination of SCF、IL 6 and IL 3 for 2 weeks only increased CFU Mix by 13.0 times and LTC IC 1.9 times. Conclusion: These results suggest that gp130 signaling in association with c kit activation may provide a novel approach fox ex vivo expansion of human primitive hematopoietic progenitors.