人脐血CD34+CD38-细胞免疫表型和染色体核型特征分析

目的 分离脐血干／祖细胞(CD34^ CD38)进行体外长期培养，观察分析其增殖、细胞表面分子标志和染色体核型的特征。方法 用流式细胞仪分选CD34-FITC和CD38-PE标记的CD34^ CD38脐血原始细胞，在含细胞生长因子IL-3、IL-6、GM-CSF、EPO、SCF和胰岛素样生长因子的干细胞培养基中培养6个月，用流式细胞术检测体外培养30d的干／祖细胞表面标记，并用G显带方法分析其染色体核型。结果 在一定培养条件下，经7～12d培养，脐血干／祖细胞(CD34^ CD38)开始增殖。培养6个月后，每孔接种1个细胞，细胞数增殖至250～350个；每孔接种10个细胞，细胞数可增殖至400～500个。每孔接种1个细胞其细胞增殖峰持续时间(8～9代)比接种10个细胞(6～7代)长：经体外长期培养增殖，细胞仍强烈显示十／祖细胞表面分子标记(CD34^ CD38^-)；细胞染色体数目、结构未见异常。结论 脐血干／祖细胞(CD34^ CD38^ )经体外特异性培养增殖，可为大量脐血干／祖细胞移植提供细胞来源。

Karyotyping and immunophenotyping analyses of the CD34 + CD38 - cells isolated from human umbilical cord blood

Objective To cultivate hematopoietic stem/progenitor cells (CD34 +CD38 -) isolated from umbilical cord blood (UCB) long termly for the observation of cell growth and expansion in vitro, surface marker expression, and chromosomal complements. Methods By flow cytometry CD34-FITC and CD38-PE labeled CD34 + and CD38 - stem/progenitor cells were isolated from UCB. The cells were cultivated in vitro for 6 months in a stem cell culture system with addition of six kinds of cell growth factors (IL-3, IL-6, GM-CSF, Epo, SCF, IGF-1). One month after cultivation, cultured cells were investigated for surface marker expression by flow cytometry and karyotype by G banding method. Results After 7~12 days cultivation, the CD34 +CD38 - stem/progenitor cells began proliferation. The proliferation rate and the peak proliferation duration were greater in 1 cell/well cultivation conditions than in 10 cells/well. The cells remained CD34 +CD38- and their karyotypic characteristics remained unchanged. Conclusion CD34 +CD38 - stem/progenitor cells from UCB may provide a larger than original amount of stem/progentor cells for transplantation after long-term cultivation in vitro.