目的　分析CD3+ TCRαβ+ DN(doublenegative)胸腺细胞的特性 ,推断其在胸腺发育中表型和功能的成熟过程。方法　分离纯化小鼠胸腺DN细胞 ,用多重染色的方法分析CD3+ TCRαβ+ DN细胞的表型和TCR库 ,并与外周淋巴结的相应细胞进行对比。结果　DN胸腺细胞为异质性细胞 ,包括CD3-DN细胞和CD3+ DN细胞 ,而CD3+ DN细胞又分为CD3+ TCRαβ+ 和CD3+ TCRγδ+ 2个亚群。其中 ,CD3+ TCRαβ+ DN细胞体积较小 ,绝大部分细胞对可的松耐受 ,细胞中能与自身反应的Vβ3+ 和Vβ11+ 细胞比例极低 ,表型较为成熟 ,与髓质型SP(singlepositive)细胞相当。结论　CD3+ TCRαβ+ DN细胞不同于CD3-TCRαβ-DN细胞 ,是一个独特的细胞亚群 ,只有在经历表型和功能的进一步成熟后才能迁出胸腺 ,移至外周 Objective To analyze the characteristics of CD3 + TCRαβ + DN (doublenegative) thymocytes and deduce its phenotypic and functional maturation in thymus development. Methods Thymus DN cells were isolated and purified. The phenotype and TCR of CD3 + TCRαβ + DN cells were analyzed by multiplex staining and compared with that of peripheral lymph nodes. Results DN thymocytes were heterogeneous cells, including CD3-DN cells and CD3 + DN cells, while CD3 + DN cells were divided into CD3 + TCRαβ + and CD3 + TCRγδ + 2 subtypes. Among them, the CD3 + TCRαβ + DN cells were smaller in volume and most of the cells were tolerant to cortisone. The proportion of Vβ3 + and Vβ11 + cells in the cells that reacted with themselves was extremely low with a relatively mature phenotype. The cells are quite Conclusions CD3 + TCRαβ + DN cells are distinct cell subsets distinct from CD3-TCRαβ-DN cells. They can move out of the thymus and move to the periphery only after further maturation of phenotype and function