脐血贴壁细胞饲养层支持造血干/祖细胞扩增的初步研究

Adherent cell layer from human umbilical cord blood and its support to ex vivo expansion of hematopoietic stem/progenitor cells

探讨来自脐血的贴壁细胞的特征及其对脐血造血干/祖细胞体外扩增的支持作用.利用流式细胞术对脐血中培养出的贴壁细胞进行了鉴定,同时观察其形态学特征,并由此建立细胞饲养层;在饲养层基础上建立共培养体系,分别体外扩增单个核细胞和CD34+细胞,观察饲养层对体外扩增的影响,并检测扩增后细胞的GEMM-CFC形成潜能.结果表明,脐血贴壁细胞呈纤维状,其CD14阳性细胞仅3.8%,而CD13、CD166、CD29阳性细胞分别为51.8%、35.6%、16.5%;与仅用外源细胞因子的非共培养体系相比,用饲养层加外源细胞因子建立的共培养体系中的单个核细胞和CD34+细胞扩增效率分别提高了2.09倍和2.94倍,并且前者扩增出的细胞比后者具有更高的GEMM-CFC形成潜能.可初步推定,从脐血中培养出的纤维状贴壁细胞具有骨髓间充质干细胞的特性.在适当的条件下,可以形成饲养层细胞,为造血干/祖细胞体外扩增提供支持基质细胞.

To investigate the feature of adherent cells from human umbilical cord blood (HUCB) and their supporting effects on ex vivo expansion of hematopoietic stem/progenitor cells (HSPCs), the morphology of the HUCB-derived adherent cells was observed and their characteristics was identified by Flow cytometry. The HUCB-derived adherent cells were used as adherent cell feeder layer to support ex vivo expansion of HSPCs. Co-culture system was established based on the feeder layer to expand the mononuclear cells (MNC) and CD34^+ cells, and the effects of feeder layer upon ex vivo expansion were observed. GEMM-CFC formations from starting cells and expanded cells were assayed. Results showed that the HUCB-derived adherent cells had typical,fibroblastic shape. CD14 was negative (3.8%), but CD13, CD166 and CD29 were positive (51.8%, 35.6%, 16.5, respectively). MNC in the culture system with adherent cell feeder layer had an expansion of 2.09-fold higher than that in the culture system without adherent cell feeder layer. CD34^+ cell in the culture system with adherent cell feeder layer had an expansion of 2.94-fold higher than that in the culture system without adherent cell feeder layer. Expanded cells in the culture system with adherent cell feeder layer had higher potentials of GEMM-CFC formation than those in the culture system without adherent cell feeder layer. HUCB-derived adherent cells showed the characteristics of mesenchymal stem cells (MSCs) cells from bone marrow. Under appropriate conditions, the adherent cells from HUCB could form the feeder layer to support long-term hematopoiesis and provide the supporting stromal cells for the ex vivo expansion of HSPCs.