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采用免疫磁珠法分离脐血CD34+造血干 /祖细胞 ,进行低氧和常氧条件下单个核细胞 (MNC)及CD34+细胞的半固体及液体培养 ,计细胞总数和集落产率 ,并通过流式细胞仪检测细胞表型和细胞周期 ,以探讨造血干/祖细胞在低氧环境下增殖分化性能的改变及其对细胞因子反应性的变化。结果显示 :CD34+细胞在低氧条件下生成的BFU E集落数 ( 32 4 8± 41 4/10 4 细胞 )明显增多 (对照为 191 2± 34 5 /10 4 细胞 ,P <0 0 1) ;在无细胞因子存在的液体培养体系中 ,低氧组的BFU E产率 ( 15 2 4± 2 2 6 /10 4 细胞 )明显高于常氧组 ( 74 2± 9 3/10 4 细胞 ,P <0 0 1) ;低氧培养细胞中CD34+细胞的比例高于对照 2 5± 1 2倍 (P <0 0 5 )。但MNC生成的BFU E在常氧和低氧条件下无显著差异。这些结果表明 :体外低氧环境能显著增加CD34+造血干 /祖细胞形成红系祖细胞的产率 ,且使其对细胞因子的依赖性降低 ,并对早期红系祖细胞的维持有增强作用 ,但对粒系祖细胞的增殖则有抑制作用
Umbilical cord blood CD34 + hematopoietic stem / progenitor cells were isolated by immunomagnetic beads method. Semi-solid and liquid culture of mononuclear cells (MNCs) and CD34 + cells under hypoxic and normoxic conditions were performed, and the total cell count and colony yield were calculated. Cytometry and cell cycle were detected by cytometry to investigate the changes of proliferation and differentiation of hematopoietic stem / progenitor cells under hypoxia and their changes in cytokine reactivity. The results showed that the number of BFU E colonies (32 4 8 ± 41 4/10 4 cells) in CD34 + cells was significantly increased under hypoxic conditions (191 2 ± 34 5/104 cells, P <0.01). In liquid culture system without cytokines, the BFU E production rate in hypoxia group (15 2 4 ± 2 2 6/10 4 cells) was significantly higher than that in normoxia group (74 2 ± 9 3/10 4 cells, P <0 01). The proportion of CD34 + cells in hypoxic cultured cells was 25 ± 1 2 times higher than that in control (P <0.05). However, MNC generated BFU E did not differ significantly under normoxia and hypoxia conditions. These results indicate that in vitro hypoxia environment can significantly increase the yield of erythroid progenitor cells that form CD34 + hematopoietic stem / progenitor cells and reduce their dependence on cytokines and enhance the maintenance of early erythroid progenitor cells, However, the proliferation of granulocyte progenitor cells is inhibited