人骨髓间充质干细胞对脐血干细胞体外扩增支持作用的研究

目的：探讨以人骨髓间充质干细胞(bone nlarrow-mesenchymal stem cells，BM-MSC)为基质的无血清培养方法，体外扩增脐血造血干细胞(cord blood stem cells，CBSC)，研究BM—MSC支持造血的功能，以能最终用于临床。方法：用含血小板生成素(TPO)、干细胞因子(SCF)、fit3／flk2配体(FL)和粒细胞-集落刺激因子(G—CSF)的无血清培养液，比较有或无MSC条件下，体外扩增脐血CD34^ 细胞两周后检测总细胞TC、CD34^ 细胞、集落形成单位(CFU)和长期培养-起始细胞(LTC—IC)增加倍数。结果：在TPO、FL、SCF、和G-CSF的作用下，经两周体外扩增后有MSC组的TC、CD34^ 细胞、CFU—GM、CFU—C和LTC—IC数较起始分别增加了427、39、125、104和16倍。单纯用上述4种细胞因子的无MSC组，TC、CD34^ 细胞、CFU—GM、CFU—C数分别增加了62、11、25、24倍，但LTC-IC只有扩增前的0．8倍。结论：以人BM—MSC为基质的无血清体外培养体系可以更有效扩增CBSC，有潜在的临床应用价值。

Bone Marrow Derived Mesenchymal Stem Cells Enhance ex vivo Expansion of Umbilical Cord CD34+ Progenitor Cells in a Serum-free Culture System

Objective: To investigate the effectiveness of ex vivo expansion of human cord blood stem cell (CBSC) using serum-free system and co-culture with human bone marrow derived mesenchymal stem cell (BM-MSC) . Methods: After 2 weeks' culture in the serum-free medium containing thrombopoietin (TPO), flt3/flk2 ligand (FL), stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF), the output of total cells (TC), CD34 + , colony forming units (CFU), and long-term culture-initiating cells were evaluated. Results: In the presence of both MSC and four cytokines mentioned above, CBSC produced an expansion of 427-fold in TC, 39-fold in CD34+ , 125-fold in CFU-C, 104-fold in CFU-GM and 16-fold in LTC-IC, after 2 weeks of incubation. By contrast, when cultured merely in the presence of the cytokines, the cell expansion for TC, CD34+, CFU-C and CFU-GM were increased by 62-fold, 11-fold, 25-fold and 24-fold, respectively. Notably, the output of LTC-IC is only 0.8 of the input. Conclusion: Our serum-free and co-culture system was shown to achieve admirable results for ex vivo expansion of CBSC, which may probably be employed for clinical purpose.