脐血造血细胞的体外扩增及其意义

In vitro expansion of human umbilical cord blood hematopiotic cells and its subpopulation

目的探讨脐血干细胞在体外扩增中的增殖效应，为脐血干细胞移植提供实验理论依据。方法用分离的脐血单个核细胞（ＭＮＣ）体外在细胞因子的作用下培养扩增，并用流式细胞仪对扩增前后的细胞增殖周期和ＣＤ３４＋细胞及亚群进行动态检测。结果脐血ＭＮＣ在体外培养５周，有核细胞数累计增加了２５２倍，ＣＤ３４＋细胞增加了５０倍，ＣＤ３３＋细胞增加２８０倍，ＣＤ１９＋、ＣＤ３＋细胞２周后便检测不出。细胞增殖周期分析显示，培养第一周，Ｇ０期细胞迅速减少，Ｓ期细胞比例很快增多。结论单只脐血在细胞因子的作用下体外扩增后完全可以满足体重５０公斤以上的成人移植之需，但选择恰当的扩增时间及制定更好的扩增策略将是非常重要的。

Objective To study the effect of expansion of cord blood stem cells in vitro.Methods The mononuclear cells of human umbilical cord blood was cultured in vitro and the cell cycle and CD34 + subset analysis was performed on these cell preparations using flow cytometry.Results After 35 days, the number of nucleated cells showed over a comulative 252 fold expansion. CD34 +cells increased 50 fold in 7～21 days. CD33 +cells increased 280 fold during 7 28 days. CD19 +and CD34 +cells disappared after 14 days. The cells remained in G 0/G 1 phase and increased in the S phase. Conclusion Single umbilical cord blood would be enough to transplant to adults if suitable time and a novel expansion strategies are set.