Wnt3a 转基因基质细胞的建立及其对脐血CD34+ 造血干/祖细胞扩增作用的研究

Wnt 信号通路在造血干/祖细胞自我更新的过程中发挥至关重要的作用 . 纯化的 Wnt3a 蛋白可以实现造血干/祖细胞的扩增 . 通过病毒转染原代小鼠骨髓基质细胞，建立转基因滋养层细胞 . 通过共培养对转基因滋养层细胞扩增 CD34+ 造血干/祖细胞的作用进行了研究 . 实验结果显示 , 与普通滋养层加细胞因子组相比，经转基因滋养层加细胞因子组培养的 CD34+造血干/祖细胞集落形成能力 (CFC) 是其 (1.55±0.06) 倍；混合集落形成能力是其 (1.95±0.26) 倍；高增殖潜能集落形成能力 (HPP-CFC) 是其 (1.45±0.40) 倍； LTC-IC 活性是其 (3.83±0.86) 倍 . 结果表明，转基因滋养层细胞通过分泌具有天然活性的 Wnt3a 蛋白能在体外有效地扩增造血干/祖细胞的数量 .

Establishment of Wnt3a-transfected Bone Marrow Stromal Cells and Study on Expansion of Human Umbilical Cord Blood CD34+ Hematopoietic Stem/Progenitor Cells In vitro

The Wnt signalling pathway plays an important role in regulation of haematopoietic stem cells (HSCs) self-renewal. Purified Wnt3a could remarkably enhance expansion of HSCs. A transgenic bone marrow stromal cells were established by using adenoviral vector mediated Wnt3a gene transfection. The effect of transgenic stromal cells as feeder layer on expansion of CD34+ cells was studied. The group of Wnt3a transfected BM stromal cells with cytokines displays the best expansion effect on of human umbilical cord blood CD34+ hematopoietic stem/progenitor cells in four groups. In vitro, expansion of CD34+ cells, when cocultured with Wnt3a modified stromal cells in the presence of cytokines, was significantly enhanced: CFC by (1.55±0.06) fold; CFC(mix) by (1.95±0.26) fold; HPP-CFC by (1.45±0.40) fold; LTC-IC by (3.83±0.86) fold ,compared with nontransgenic stromal cells with cytokines group. These results strongly suggest that Wnt3a modified BM stromal cells may be a suitable feeder layer for expansion of haematopoietic stem/progenitor cells in vitro.