TGF-β1对脐血体外扩增中造血祖细胞生物学特性影响

Effect of TGF-β1 on Biological Characteristics of Umbilical Cord Blood Hematopoietic Progenitor Cells during ex-vivo Expansion

为了了解TGF β1对扩增中脐血 (UCB)造血祖细胞 (HPC)增殖和分化等生物学特性的影响 ,探讨利用其进行UCB HPC体外扩增的可行性 ,在含有若干细胞因子的UCBCD133+ 细胞体外扩增体系中加入不同浓度的TGF β1,对扩增细胞的有核细胞 (NC)数、免疫表型、细胞周期、祖细胞集落及粘附分子表达等进行了动态观察。结果显示 ,TGF β1各组NC总数及其扩增倍数均低于对照组 ,且呈明显的剂量负相关性。扩增中TGF β1各组的CD34+ 、CD133+ 、CD34+ CD38-细胞的比例、细胞总数及其扩增倍数均明显高于对照组。在扩增早期 ,TGF β1各组的CFU GM ,CFU mix和HPP CFC集落的产率均高于对照组。高浓度TGF β1组的S期细胞比例明显减少 ,而G1/G0 期的细胞明显增加。对粘附分子表达的检测表明 ,TGF β1能够上调CD4 9d ,CD11a ,和CD5 4的表达 ;TGF β1各组表达CD4 9d ,CD11a和CD5 4细胞的比例明显高于对照组 ,而表达这些粘附分子的CD34+ 细胞的比例也明显高于对照组。结论 :适当剂量的TGF β1能够促进CD133+ 细胞的扩增 ,延缓和减少扩增中HPC的过度分化 ,提高扩增细胞中造血祖细胞的含量 ,同时还能上调扩增细胞的部分粘附分子的表达 ,从而提高扩增细胞的植入能力 ,对提高UCB体外扩增的质量具有重要意义。

To investigate the effects of TGF-β1 on biological charateristics of hematopoietic progenitor cells (HPC) in umbilical cord blood (UCB) during ex-vivo expansion and feasibility of using it for expansion of UCB HPC, different concentrations of TGF-β1 were added in the serum-free medium containing a combination of hematopoietic growth factors for expansion of UCB CD133 + cells and enumeration of nucleated cells (NC), progenitor colonies, immunophenotyping, cell cycle and expression of adhesion molecules of the NC were monitored at every interval. The results showed that total number and expansion of NC from all groups of TGF-β1 were remarkably less than those in control at each interval. However the content and total numbers as well as expansion of CD34 +,CD133 +,CD34 +CD38 - and CD34 +CD133 + cells from all groups of TGF-β1 were more than those in control at each interval during expansion; the plating efficiency and expansion of CFU-GM,CFU-mix and HPP-CFC from NC of TGF-β1 group were more than those in control at each interval. The contents of cells in G 0/G 1 phase of NC of TGF-β1 group at every interval were high. Meanwhile, TGF-β1 could elevate the expression of some adhesion molecules on NC during expansion such as CD54, CD49d and CD11a, and the contents of CD34 + cells coexpressing these adhesion molecules in NC of TGF-β1 group were significantly more than those in control at each interval. In conclusion appropriate dose of TGF-β1 could accelerate expansion of CD133 + cells, delay and decrease over-differentiation of HPC, increase the content of HPC in expanded products, upregulate the expression of adhesion molecules on expanded HPC, thus it could pomote engraftment of expanded progenitor cells and advantage the ex-vivo expansion of UCB HPC.