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

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

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.

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 stern/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 stern/progenitor cells in vitro.