Kelly K A, Scollay R
Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
Int Immunol. 1990;2(5):419-25. doi: 10.1093/intimm/2.5.419.
The thymus plays an integral role in the development and production of T lymphocytes. However, thymocytes differ markedly in their phenotypic characteristics from the T cells normally found in the peripheral lymphoid organs. We have examined the phenotypic characteristics of recent thymic emigrants and compared them with both mature phenotype thymocytes (CD4+ CD8-CD3+ and CD4-CD8+ CD3+) and lymph node T cells. Recent thymic emigrants were defined as those fluorescein-positive cells found in the lymph node up to 16 h after intrathymic injection of fluorescein. Most cells emigrating from the thymus expressed CD3 and either CD4 or CD8, indicating maturity. Recent thymic emigrants, like mature phenotype thymocytes, were slightly larger on average than peripheral T cells, but this differential was lost within 24 h of emigration. Also like mature thymocytes but unlike peripheral T cells, some recent emigrants expressed heat-stable antigen. This did not change within 24 h of emigration. The antigen CD44 (Pgp-1, Ly-24) was expressed on a proportion of mature thymocytes, recent thymic emigrants, and peripheral T cells, and its expression did not show any clear relationship to maturity. The antigen CD45R also did not show marked changes associated with maturity, but our data do not parallel the published data of the expression of CD45R in the human. We conclude that recent thymic emigrants are phenotypically mature with respect to some antigens but not others. None of the antigens we investigated could have been used to uniquely distinguish recent thymic emigrants from peripheral T cells or from mature thymocytes.
胸腺在T淋巴细胞的发育和产生过程中发挥着不可或缺的作用。然而，胸腺细胞在表型特征上与外周淋巴器官中正常发现的T细胞存在显著差异。我们已经检测了近期胸腺迁出细胞的表型特征，并将它们与成熟表型胸腺细胞（CD4+CD8-CD3+和CD4-CD8+CD3+）以及淋巴结T细胞进行了比较。近期胸腺迁出细胞被定义为在胸腺内注射荧光素后16小时内在淋巴结中发现的荧光素阳性细胞。大多数从胸腺迁出的细胞表达CD3以及CD4或CD8，表明其成熟。近期胸腺迁出细胞与成熟表型胸腺细胞一样，平均而言比外周T细胞略大，但这种差异在迁出后24小时内消失。同样与成熟胸腺细胞相似但与外周T细胞不同的是，一些近期迁出细胞表达热稳定抗原。这在迁出后24小时内没有变化。抗原CD44（Pgp-1，Ly-24）在一部分成熟胸腺细胞、近期胸腺迁出细胞和外周T细胞上表达，其表达与成熟度没有明显关系。抗原CD45R也没有显示出与成熟相关的显著变化，但我们的数据与已发表的关于人CD45R表达的数据不一致。我们得出结论，近期胸腺迁出细胞在某些抗原方面表型成熟，但在其他抗原方面并非如此。我们研究的任何一种抗原都不能用于唯一地将近期胸腺迁出细胞与外周T细胞或成熟胸腺细胞区分开来。
