小鼠骨髓lin^-CD117^+造血干细胞定向分化成浆细胞样树突状细胞的研究

The Mice Bone Marrow-derived Hemopoietic Stem Cells of lin^-CD117^+ Phenotype Showing Potential of Directional Differentiation to Plasmacytoid Dendritic Cells

目的观察小鼠骨髓lin-CD117+造血干细胞大量增殖分化成浆细胞样树突状细胞(pDC)的方法。方法采用免疫磁珠法分离正常C57小鼠骨髓的lin-CD117+干细胞,加入干细胞因子(SCF)及白介素(IL)-3促进增殖。9天后,停用SCF和IL-3,加入粒细胞-巨噬细胞集落刺激因子(GM-CSF)、IL-4和IL-10诱导发育成pDC,或加入肿瘤坏死因子(TNF)-α促进细胞成熟。光学显微镜和扫描电镜观察pDC形态,经流式细胞法检测免疫表型和吞噬功能。结果SCF和IL-3促进造血干细胞大量增殖;与成熟DC比较,pDC具有明显的未成熟DC形态特征,表型呈CD117和CD11c阳性,I-A/I-E低表达及CD40、CD80和CD86阴性,且吞噬功能较弱。结论小鼠骨髓lin-CD117+造血干细胞可经细胞因子诱导大量增殖,并向pDC转化。

Objective To establish a stable method for obtaining large quantity of plasmacytoid dendritic cells （pDCs） derived from lin^-CD117^＋ stem cells in the mice bone marrow. Methods The lin^-CD117^＋ hemopoietic stem cells were obtained from the bone marrow of C57 mice by magnetic ＂affinity cell sorting. The stem cell factor （SCF） and interleukin （IL）-3 were added to enhance the proliferation of cells and then the granolocyte-macrophage colony-stimulating factor （ GM-CSF）, IL-4 and IL-10 were used to induce directional differentiation to pDCs, or TNF-α alone to mature the cells. The morphological features of pDCs were observed under optical and scanning electron microscopes. The surface markers and phagocytosis function of cells were analyzed by flow cytometry. Results A large number of generation of lin^-CD117^＋ cells was found after the induction of SCF and IL-3. The markers of CD117 and CD11c on pDCs were strongly, I-A/I-E weakly and CD40, CD80 and CD86 had not been seen. The pDCs had the morphological features of immature DCs, and showed weaker function of phagocytosis than mature DCs did. Conclusions The mice bone marrow-derived hemopoietic stem cells of lin^-CD117^＋ phenotype could differentiate to pDCs with the induction of cytokines.