低剂量辐射对TCR／CD3和CD25在小鼠胸腺细胞浆膜表达的影响

本文首次报道低剂量Ｘ射线全身照射促进胸腺细胞表面ＴＣＲ＿（α．β）、ＣＤ３和ＣＤ２５等分子的表达。已知低剂量辐射可加速胸腺细胞更新和增殖。为了探讨低剂量辐射对胸腺细胞成熟过程的影响，用免疫荧光流式细胞术检测了７５ｍＧｙＸ射线全身照射后ＴＣＲ／ＣＤ３和ＣＤ２５的表达。发现照射后４～２４ｈＴＣＲ／ＣＤ３的表达随时间推移逐步增升，表明低剂量辐射促进胸腺细胞成熟。照射后２４ｈ丝裂原激活的胸腺细胞表达ＣＤ２５显著增强，提示胸腺细胞的功能活性增高。讨论了胸腺细胞表面上述分子表达变化在促进细胞信息传递中的意义。

Effect of low dose radiation on the expression of TCR/CD3 and CD25 molecules in the plasma membrane of mouse thymocytes

Whole- body irradiation(WBI)with low dose X-rays could facilitate theexpression of TCR( T cell receptor), CD3 and CD25 molecules on the surface of mousethymocytes is reported for the first time in the paper.It has been reported from thislaboratory that low dose radiation could potentiate the thymocytes renewal.In order tostudy the effect of low dose radiation on the process of maturation and differentiation ofthymocytes,flow cytometry with immunofluorescence was used to examine the changes inexpression of TCR/CD3 and CD25 molecules on the thymocytes after WBI with 75mGyX-rays.It was found that 4-24 hours after irradiation the expression of TCR/CD3 onthe surface of thymocytes increased with time, suggesting an expedited maturation anddifferentiation of the thymocytes. The expression of CD25 ( interleukin 2 receptor)of theCon A-stimulated thymocytes was markedly potentiated 24h after irradiation, indicatingan up-regulation of their functional activity. The significance of the increased expressionof these molecules on thymocytes and its role in the facilitation of T lymphocyte signaltransduction after low dose radiation were discussed.