脐带血造血干细胞的“质”“量”研究

目的 对脐带血造血干细胞移植的“质”“量”作出评估，使其更广泛有效地应用于临床。 方法 利用免疫磁珠分离法、ＦＡＣＳ分析与分选、体外液体培养，铺展贴壁等方法对脐带血ＣＤ３４＾＋造血干、粗细胞及其的数量、体外增殖分化性能、生长因子扩增效应，植入成人骨髓基质效率等进行研究，数据经ｔ检验。结果 脐带血有核细胞、ＣＦＣｓ、ＣＤ３４＾＋细胞及其亚群等的绝对数量明显低于常规骨髓移植所需的细胞数量，但脐带血ＣＤ

Qualitative and quantitative studies of human umbilial cord blood hematopoietic stem cells

Objective To evaluate the quality and quantity of human umbilial cord blood hematopoietic stem cells for transplantation, the percentage, abilities of proliferation and differentiation, expansion responses and grafting efficiency of CD34⁺ cells and their subpopulations from umbilical cord blood were studied.Methods CD34⁺ cells and their subsets (CD34⁺CD38⁺ and CD34⁺CD38^-) were isolated from human umbilical cord blood by using MACS or FACS system, cultured and expanded with hematopoietic growth factors (HGFs) in semi solid and liquid culture systems, and the grafting efficiency was evaluated by Panning assay. Results The percentage of CD34⁺CD38^- subset in cord blood was much higher (9 5%) than that in bone marrow or peripheral blood (4%) (P<0.01 ). More hematopoietic colony formation from cord blood than that from bone marrow or peripheral blood was observed. With addition of HGFs, the total uncleated cells increased by 500.0±82.5-fold, the hematopoietic progenitor cells by 94.1±28.6-fold and the CD34⁺ cells by 24.0±3.8-fold. Only 36% of CD34⁺ cells were taken in a pre formed adult bone marrow stroma in a short time (2hr), but 68%-89.6% of those pretreated with GM CSF and / or IL 3 for 6-8hr were taken in the stroma (P<0.01 ). Conclusions It is possible to expand cord blood CD34⁺ cells ex vivo to improve their grafting efficiency for utilization of cord blood stem cells in treatment of acute radiation sickness, transplantation and therapeutic gene transfer.