中文摘要：

目的比较研究小鼠体内外胸腺细胞CD4^＋CD25^＋双阳性T细胞发育的动态变化，为天然调节性T细胞的研究提供基础数据。方法采用14．5天龄胚鼠胸腺进行体外培养，以FACS检测不同时间点胸腺细胞的表型变化，同时计数每个胸腺小叶的细胞数变化。结果胸腺在体内发育的第14．5、15、16、17、18、19天CD4^＋CD25^＋双阳性T细胞的比例、细胞的数量与在体外胸腺培养的第1～6天在胸腺细胞中的比例、细胞数发育趋势相似；CD4^＋CD25^＋双阳性T细胞占CD4^＋T细胞的比例分别为8．19％、16．41％、24．06％、13．62％、8．10％、2．35％，占CD25^＋细胞的比例分别为0．34％、1．08％、2．40％、10．59％、32．51％、34．04％。与体内结果相似，胸腺细胞体外培养的结果显示：在培养的第1～6天，CD4^＋CD25^＋T细胞占CD4^＋T细胞的比例分别为58．29％、12．14％、6．08％、17．78％、9．06％、4．04％，占CD25^＋T细胞的比例分别为3．75％、10．81％、17．20％、51．93％、61．64％、80．06％。结论体外培养的CD4^＋CD25^＋双阳性胸腺细胞数量和比例变化与体内发育变化趋势一致，在体外培养第4天（约等于18．5天胚鼠）和体内发育的第17天该群细胞比例最大．这将为天然调节性T细胞的发生、发育学研究提供有效的参考。

英文摘要：

Purpose To compare the dynamic changes of CD4^＋ CD25^＋ thymocytes development in vivo and in vitro. Methods Fetal mice thymus lobes were removed at the age of 14.5 days and cultured in complete RPMI-1640 with 20% FBS in vitro. Phenotypes of the thymocytes were analyzed by FACS and the number of cells per lobe was counted. Results It revealed that from day 14. 5 to day 19, the number and the percentage of the CD4^＋ CD25^＋ thymocytes varied similarly as their development as in vitro culture in 6 days. The CD4^＋ CD25^＋/CD4^＋ percentage was 8. 19%, 16.41%, 24. 06%, 13.62%, 8.10%, 2.35% for each and the CD4^＋ CD25^＋/CD25^＋ was 0.34%, 1.08%, 2.40%, 10.59%, 32.51%, 34.04% respectively. In vitro data showed that during the 6 days in vitro culture, the CD^4＋ CD25^＋/CD4^＋ percentage was 58.29%, 12.14%, 6.08%, 17.78%, 9.06%, 4. 04% and the CD4^＋ CD25^＋/CD25^＋ percentage was 3.75%, 10.81%, 17.20%, 51.93%, 61.64%, 80.06% for each. Conclusions These results suggested that the in vitro and in vivo CD4^＋ CD25^＋ thymocytes development was similar, with its peak development on the 4^th day in vitro and the 17^th days in vivo. The above data might help to understand the development of naturally arising CD4^＋ CD25^＋ regulatory T cells.