脐血造血细胞中AC133抗原表达及其功能特征研究

目的 探讨AC133抗原在正常人造血细胞中表达的意义。方法 采用双色直接免疫荧光标记法,使用流式细胞仪测定脐血中造血细胞的免疫表型。通过祖细胞集落形成单位（CFC）和长期培养启动细胞（LTC-IC）的测定对脐血中AC133^ ,CD34^ 和AC133^-CD34^ 细胞的造血潜能进行了研究。结果 脐血单个核细胞（MNCs)中AC133^ 细胞比例为0.67%,AC133^ 细胞中93.4%表达CD34抗原,94.2%为PKH26阳性,虽然三群细胞产生的CFC总数差异无显著性。但AC133^ 细胞中50%以上为粒-单集落形成单位,CD34^ ,AC133^-CD34^ 细胞中60%和80%以上为红系集落形成单位,AC133^ 细胞产生的LTC-IC显著高于CD34^ 和AC133^-CD34^ 细胞。体外培养7d,AC133^ 细胞组细胞总数和CFC分别扩增28.2和7.1倍,6.8%细胞仍保持PKH26阳性。结论 脐血中早期造血干/祖细胞富集在AC133^ 细胞群中,AC133^ 细胞在体外具有较强的增殖能力,既能产生大量的早期定向祖细胞,又能保持一定数量的早期干/祖细胞,AC133抗原可作为临床分选造血干/祖细胞的有效标志。

The expression and functional characteristics of AC133 antigen in cord blood hematopoietic cells

Objective To explore the significance of AC 133 antigen expression on cord blood (CB) hematopoietic cellls Methods The immunophenotype of CB hematopoietic cells was analyzed by flow cytometric two color direct immunoflurescence method Hematopoietic activity of AC + 133 , CD + 34 and AC - 133 CD + 34 cells in CB was examined by analyzing clonogenic capacity, number of LTC IC and ex vivo expansion ability Results AC + 133 cells consisted of 0 67% of the total CB MNCs Of the AC + 133 cells, 93 4% expressed CD 34 antigen and 94 2% was PKH + 26 ? Although the total number of CFC was the same in the AC - 133 CD + 34 fraction as in the CD + 34 and AC - 133 fractions, the number of LTC IC was much higher in the AC + 133 fraction In addition, the features of the colonies grown from these three fractions were quite different Approximately 50% of the colonies derived from the AC + 133 fraction were CFU GM, whereas more than 60% of the colonies derived from the CD + 34 fraction and 80% of the colonies derived from the AC - 133 CD + 34 fraction were BFU E After 7 d ex vivo expansion, the total number of cells and CFC increased 28 2 fold and 7 1 fold respectively in AC + 133 cell populations, 6 8% of the cells was PKH + 26 . Conclusions These findings suggest that the early stem/progenitor cells of CB are enriched in AC + 133 fraction, AC + 133 cells contain higher proliferative efficiency during ex vivo culture It can generate either committed progenitors or early stem/progenitors AC 133 antigen would be a useful marker for clinical selection of hematopoietic stem/progenitors