脐血造血干/祖细胞体外定向诱导扩增的研究

目的　观察不同因子组合在体外对脐血 (CB)中的巨核系等造血祖细胞的诱导扩增作用。方法　用体外液体悬浮培养法 ,将白细胞介素 3(IL 3)、白细胞介素 6 (IL 6 )、血小板生成素 (TPO)、脐血血浆 (CBP)作为刺激因子 ,添加不同的细胞因子组合 ,对CB的单个核细胞 (MNC)短期培养 2 1d。在培养的 0、7、14、2 1d检测新鲜细胞和培养细胞中的有核细胞数 (NC)、巨核系祖细胞 (CFU Mk)、粒巨噬系祖细胞 (CFU GM)、混合系祖细胞 (CFU GEMM)增殖倍数。结果　在 2 1d内 ,3个实验组的NC数 ,CFU GM、CFU Mk、CFU GEMM都有不同程度的增加 ,其中NC、CFU GM在培养的 2 1d达到高峰。CFU Mk、CFU GEMM在培养的 14d达高峰。在含有TPO的实验组中 ,CFU Mk的增殖倍数高于不含TPO的实验组 ,CFU GM、CFU GEMM增殖的倍数也高于不含TPO的实验组。含有CBP的实验组对CFU GM、CFU Mk、CFU GEMM有明显的促增殖作用。结论　CB中的含有丰富的造血干 祖细胞 ,可以在不同细胞因子的刺激下进行定向扩增 ,TPO可以促进干 祖细胞向巨核系分化 ,对粒巨噬系祖细胞也有促进作用。脐血血浆可以作为协同刺激因子促进CB中干 祖细胞增殖。

Expansion of cord blood primitive and committed progenitors cells in vitro

Objective To establish a method for ex vivo cord blood stem cell expansion,increase the number of the stem/progenitor,especially megakaryocyte progenitors so as to decrease the thrombocytopenia period after CBT.Methods Mononuclear cells (MNC) from 20 cord blood samples were cultured in presence of different cytokines:group 1:IL 3,IL 6,group 2:IL 3,IL 6,TPO,group 3:IL 3,IL 6,TPO and cord blood plasma.The final concentration of the cytokines was 50ng/ml.The control group had all medium except the cytokines and cord blood plasma.The cells were cultured for 21 days.At every 7 days,tests were done for nucleate cells number,CFU GM,CFU Mk,and CFU GEMM.Results At different times and in different groups,there were different changes.For NC,maximal increase were obtained in group 3 on day 21,which was 239.65±153.48.For CFU GM,the biggest expansion occurred on day 21 in group 3,the number being 184.17±140.40.For CFU Mk,the biggest expansion was obtained on day 14 in group 3,with the number of 135.34±105.20. The immature progenitor CFU GEMM achieved the max increase in group 3 on day 14,the number was 49.39±36.68. Conclusion The expansion of CFU Mk progenitor cells can be obtained in the presence of IL 3,IL 6,TPO.This combination also enhances the expansion of CFU GM and CFU GEMM.Addition of cord blood plasma can promote the expansion of mature and immature progenitor cells.