摘要
目的:探讨骨髓间充质干细胞(MSC)的黏附分子表达及其对脐血造血干/祖细胞体外增殖的支持作用。方法:取正常骨髓单个核细胞贴壁培养,梭形细胞完全融合后传代,用流式细胞仪检测免疫表型;将脐血CD34+细胞接种到MSC或其他培养液上,比较不同培养条件对造血细胞扩增能力及黏附分子表达的影响。结果:MSC在体外培养中分为成纤维样成熟MSC(mMSC)和体积很小的圆形RS(rapidlyselfrenewingcells)细胞;两群细胞的CD34、CD45、CD3、CD19、CD33、HLADR、CD38均为阴性,而CD90、CD105、CD166、CD29、CD44、CD49e、CD54、CD13呈阳性,但RS细胞表面抗原表达的阳性率和平均荧光强度都明显低于mMSC,而CD117的表达高于mMSC;脐血CD34+细胞在MSC和细胞因子作用下,扩增8d后有核细胞、CD34+、CD34+CD38-细胞和CFUCs分别扩增(145.57±17.89)、(37.47±13.78)、(69.78±50.07)、(10.74±5.89)和(20.73±5.54)倍,均显著高于对照组,扩增后CD34+细胞的ALCAM、VLAα4、VLAα5、VLAβ1、HCAM、PECAM和LFA1表达较扩增前无显著变化。结论:MSC是一个异质性的细胞群体,可为造血干细胞(HSC)体外扩增提供适宜的微环境,有助于抑制HSC分化并保持其归巢能力。
Objective：To explore the expression of adhesion molecules on human bone marrow-derived mesenchymal stem cells （MSC） and the effect of MSC on ex vivo expansion of cord blood （CB） hematopoietic stem cells （HSC）. Method： MSC were obtained from normal human bone marrow aspirates. Their differentiation function were investigated with specific induction culture system and phenotype were identified by flow cytometry. CB CD34^＋ cells were expanded on MSC layer or MSC-free culture systems and the effect of MSC on expansion poten tial and expression of adherent molecules on CB CD34^＋ cells were investigated. Result： Two different subpopulations were observed in the ex vivo culture. The fibro-like cell was called mature MSC （mMSC） and the smaller round cell was defined rapidly self-renewing cells （RS cells）. Both of the two populations were negative on CD34 ,CD45 ,CD3 ,CD19, CD33. HLA DR and CD38, while positive on the expression of CD90. CD105. CD166, CD29,CD44,CD49e,CD54,CD13, However, the expression of these antigens on RS cells was weaker than that of mMSC, but CDll7 was more expressed when compared with the latter. After culturing on MSC layer with addi tional cytokines for 8 days, increases in the absolute numbers of nuclear cells, CD34^＋ , CD34^＋ CD38^- cells and CFU-Cswere （145.57±17.89） fold, （37.47±13.78） fold, （69.78±50.07） fold, （10.74±5.89） fold and （20.73±5.54） fold, respectively, significantly higher than that cultured in the presence of cytokines alone. The expression of ALCAM, VLA-α4, VLA-α5, VLA-β1, HCAM, PECAM and LFA-1 on CD34^＋ cells remained unaffected. Conclusion： Adult MSC are heterogenous in that there are two distinct morphologically populations. The RS cells appear to be the more primitive stromal progenitors. The addition of MSC as a feeder layer provided improved conditions for expansion of CB CD34^＋ cells and may serve to inhibit their differentiation and remain their homing ability.
出处
《临床血液学杂志》
CAS
2005年第5期262-265,共4页
Journal of Clinical Hematology
