CD271及CD133用于阳性分选富集骨髓间充质干细胞的比较

本研究旨在通过对CD271（低亲和性神经生长因子受体，low affinity nerve growth factor receptor，LNG—FR）及CD133免疫磁珠阳性分选富集骨髓间充质干细胞（mesenchymal stem cells，MSCs）的比较，选出一种相对理想的从骨髓中富集间充质干细胞的免疫磁珠分选方法。采用免疫磁珠的方法得到骨髓单个核细胞中的CD271^＋细胞及CD133^＋细胞；将得到的细胞分别进行培养，14天后计数成纤维细胞集落形成单位（colony forming unit—fibro—blast，CFU—F）；对每个传代细胞进行计数，绘制细胞增殖曲线；取两种方法得到的细胞培养至3代以后，流式细胞术检测细胞表面抗原，通过细胞形态及免疫化学染色鉴定比较成骨及成脂肪定向诱导分化。结果表明：CD271阳性分选纯度为（89．50±0．98）％，CD133阳性分选纯度为（88．03±3．06）％；1×10^4个CD271^＋细胞培养后产生的CFU—F数目是1×10^4个CD133^＋细胞培养后形成CFU—F数目的2倍，CD271^-细胞培养后无CFU—F形成，而CD133^-细胞培养后可形成少量的CFU—F；两种方法得到的细胞培养至第3代后表型基本一致，即CD34^-、CD14^-、CD45^-、CD90^＋、CD29^＋、CD44^＋、CD105^＋、CD73^＋；CD271^＋细胞的增殖能力比CD133^＋细胞的高出3倍，而且具有更强的成骨、成脂肪分化潜能。结论：虽然CD271及CD133阳性分选都可以得到间充质干细胞，但相比之下，CD271阳性分选得到的间充质干细胞有更强的增殖和分化能力，因而CD271阳性分选是一种相对理想的从骨髓中富集阃充质干细胞的免疫磁珠分选方法。

Comparison between CD271 and CD133 Used for Immunomagnetic Positive Sorting Enriching in Mesenchymal Stem Cells from Bone Marrow

This study was aimed to find a better method to isolate and enrich mesenchymal stem cells (MSCs)from bone marrow between CD271 (low affinity nerve growth factor receptor, LNGFR) and CD133 used for immunomagnetic positive selections through comparison of characteristics of MSCs isolated by these two agents. CD271+ and CD133+ cells were isolated from bone marrow and their colony forming unit-fibroblast (CFU-F) efficiency and proliferative capacity were assessed. Cell surface phenotype, adipogenic and osteogenic inductions were also assayed on the cells (after passage 3) isolated by both methods. The results showed that the purities of immunomagnetically selected CD271+ and CD133+ cells were (89.50+/-0.98)% and (88.03+/-3.06)% respectively. The CFU-F median frequency of CD271+ cells was 3 times as high as that of CD133+ cells, no CFU-F was observed in CD271- cells, while a few CFU-F was found in the CD133- cells. Phenotype of cells (after passage 3) isolated by the two methods was same, that is CD34-, CD14-, CD45-, CD90+, CD29+, CD44+, CD105+, CD73+. CD271+ cells possessed faster proliferation and stronger osteogenic and adipogenic differentiation potential than that of CD133+ cells. It is concluded that as compared with CD133 positive selection, CD271 positive selection is a better method for isolating and enriching mesenchymal stem cells from bone marrow.