To elucidate the role of fetal bone marrow stromal cells(FBMSC) in cooperation with exogenous cytokines in supporting the in vitro expansion of cord blood CD34 + cells which were purified by negative immunomagnetic se...To elucidate the role of fetal bone marrow stromal cells(FBMSC) in cooperation with exogenous cytokines in supporting the in vitro expansion of cord blood CD34 + cells which were purified by negative immunomagnetic selection, FBMSCs were cultured with different combinations of cytokines including SCF, IL-3, IL-6, FL, G-CSF and EPO in a 14-day liquid culture system. The results showed FBMSC plus SCF, IL-3, IL-6, FL and EPO was the most effective combination which increased total nucleated cells, CFU-GM, BFU-E and CD34 + cells by (692.4±52.7) fold, (237.1±106.6) fold, (114.8±32.8) fold and (25.3±10.1) fold, respectively. Our studies indicated that fetal bone marrow stromal cells combined with above-mentioned cytokines can efficiently expand cord blood CD34 + cells.展开更多
文摘To elucidate the role of fetal bone marrow stromal cells(FBMSC) in cooperation with exogenous cytokines in supporting the in vitro expansion of cord blood CD34 + cells which were purified by negative immunomagnetic selection, FBMSCs were cultured with different combinations of cytokines including SCF, IL-3, IL-6, FL, G-CSF and EPO in a 14-day liquid culture system. The results showed FBMSC plus SCF, IL-3, IL-6, FL and EPO was the most effective combination which increased total nucleated cells, CFU-GM, BFU-E and CD34 + cells by (692.4±52.7) fold, (237.1±106.6) fold, (114.8±32.8) fold and (25.3±10.1) fold, respectively. Our studies indicated that fetal bone marrow stromal cells combined with above-mentioned cytokines can efficiently expand cord blood CD34 + cells.
文摘本研究探讨人骨髓间充质干细胞(human mesenchymalstem cells,hMSC)对同种异体CD4+CD25+调节T细胞的作用,进一步查明人骨髓间充质干细胞对T淋巴细胞免疫调节作用的可能机制。从人骨髓中分离培养hMSC,通过免疫组织化学方法检测其表面标记并进行鉴定。从非亲缘供者健康人外周血中提取单个核细胞,在IL-2作用下体外培养,实验组加入不同数量级hMSC(1×103,1×104,1×105)共培养5天,对照组加入PBS。于结束培养前18小时经3H-TdR标记后用β液体闪烁计数仪检测T淋巴细胞增殖,流式细胞术检测各组CD4+CD25+T细胞的百分率,RT-PCR检测各组细胞Foxp3的相对表达量(Foxp3/β-actin),ELISA分别测定上清中TGF-β、IL-10、IFN-γ和IL-12的表达。Pearson检验分析Foxp3相对表达量与CD4+CD25+T细胞百分率的相关性,以及Foxp3相对表达量、CD4+CD25+T细胞百分率与T淋巴细胞增殖程度(counts per minute,CPM值),细胞因子TGF-β、IL-10、IFN-γ和IL-12表达量的相关性。结果表明:hMSC能明显抑制T淋巴细胞增殖,且抑制作用与hMSC呈剂量依赖性;实验组各组CD4+CD25+T细胞亚群含量以及Foxp3相对表达水平均较对照组明显增加(p<0.05),且实验组间比较差异仍具有统计学意义(p<0.05);Foxp3表达水平、CD4+CD25+T细胞百分率与T淋巴细胞增殖水平呈明显负相关(p<0.05),与TGF-β、IL-10表达量呈明显正相关,而与IFN-γ和IL-12的表达无明显相关性。结论:hMSC呈剂量依赖性抑制同种异体淋巴细胞增殖,其机制可能与hMSC通过分泌TGF-β、IL-10促进CD4+CD25-T细胞向表达Foxp3的CD4+CD25+调节T细胞转化,进而发挥免疫抑制作用有关。
