人骨髓基质细胞促进脐血CD34+细胞的体外扩增和对NOD/SCID小鼠的植入

目的 研究人骨髓基质细胞(MSC)促进脐血CD34+细胞体外扩增及植入能力的作用.方法 分离、培养正常人的MSC作为滋养层细胞.在TPO、SCF、FL和G-CSF刺激下,比较有、无MSC滋养层细胞对扩增脐血CD34+细胞后,CD34+细胞和CFU数的增加倍数,以及植入非肥胖性糖尿病/重症联合免疫缺陷(NOD/SCID)小鼠的能力.结果 以骨髓MSC为滋养层细胞的培养体系可以更加有效地扩增脐血CD34+细胞.体外扩增1周总细胞数(TNC)、CD34+细胞和CFU的均数分别增加111.6、19.3和58.0倍;体外扩增2周后TNC、CD34+细胞和CFU的均数分别增加532.8、41.3和563.5倍.脐血细胞输入NOD/SCID小鼠6周后,移植未扩增脐血细胞的对照组小鼠骨髓细胞中人CD45+细胞比例仅为1.2%～3.7%;移植单纯细胞因子刺激扩增组小鼠骨髓中,人CD45+细胞比例为7.6%～12.1%;以MSC为滋养层扩增的脐血细胞移植组,人CD45+细胞比例达到45.3%～59.1%.结论 以人骨髓MSC为作为饲养层细胞,不但可以更加有效扩增脐血CD34+细胞,而且可以促进脐血细胞植入NOD/SCID小鼠的能力,有潜在的临床应用价值.

Human bone marrow stromal cells facilitate the cord blood CD34+ cells ex vivo expansion and short-term engraftment in NOD/SCID mice

OBJECTIVE: To explore the potential of human bone marrow stromal cells (MSCs) as the feeding-layer to promote ex vivo expansion of cord blood CD34+ cells and engraftment of the expanded cells in NOD/SCID mice. METHODS: Human MSCs were routinely isolated and cultured. MSCs at passage 3 were used as feeding-layer for the expansion of cord blood CD34+ cell in the presence of thrombopoietin (TPO), flt3/flk2 ligand (FL), stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF). The engraftment potential between unexpanded and expanded cord blood cells transplanted into NOD/SCID mice was compared. RESULTS: The total nucleated cells (TNC), CD34 cells and colony forming units (CFUs) in the MSC feeding culture were increased by 111.6-, 19.3- and 58-fold after 1 week expansion and 532.8-, 41.3- and 563.5- fold increased after 2 weeks expansion respectively as compared with that in non MSC feeding culture. In transplant experiment, the percentage of human CD45+ cells (45.3% -59.1%) in bone marrow of recipient mice transplanted with the MSC feeding expanded cells was the highest in all the groups at six weeks after transplantation. CONCLUSION: Human MSCs enhance CB CD34+ cells in vitro expansion and their capacity of short-term engraftment in NOD/SCID mice.