X射线全身照射对小鼠脾细胞转铁蛋白受体表达的影响

Effects of whole body irradiation with X rays on expression of TfR in splenocytes of mice.

目的转铁蛋白受体（ＴｆＲ）是Ｔ淋巴细胞受抗原或丝裂原刺激后表达在细胞表面的重要受体之一，与Ｔ细胞的活化和增殖有着密切关系。目前尚未见国内外有关ＴｆＲ辐射效应研究的报道。研究大剂量电离辐射后ＴｆＲ表达的变化及作用，对阐明辐射抑制机体免疫功能的机制有着重要意义。方法本文采用流式细胞术的方法观察了不同剂量Ｘ射线全身照射对小鼠脾细胞ＴｆＲ表达的影响以及４ＧｙＸ射线全身照射后不同时间ＴｆＲ表达的变化。结果０５～６ＧｙＸ射线全身照射后２４小时，脾脏ＴｆＲ阳性细胞数从１Ｇｙ开始随照射剂量的增加而下降，且呈明显的剂量依赖性。４ＧｙＸ射线全身照射后１２～７２小时，脾脏ＴｆＲ阳性细胞数于照后１２小时开始下降，２４、４８小时降至最低值（Ｐ＜０．０５，Ｐ＜０．０１），７２小时开始回升。结论大剂量电离辐射抑制小鼠脾细胞ＴｆＲ的表达，并有明显剂量依赖性；ＴｆＲ表达的下降可能与辐射抑制ＩＬ２的分泌和ＩＬ２受体的表达有关。

Objective\ Transferrin receptor(TfR) is one of important membrane receptors expressed in T cells stimulated with antigens or mitogens and is closely related with the activation and proliferation of T lymphocytes. Researches on radiation effects of TfR expression have not been reported yet. Studying the change and function of TfR expression after high dose ionizing radiation is important for clarifying the mechanism of ionizing radiation inhibiting immune function. Methods TfR expressions in lymphocytes in mouse spleens in different doses and at different time after the whole body irradiation (WBI) with X rays were examined using flow cytometry. Results At 24 hours after the WBI with 0.5-6 Gy X rays, TfR positive splenocytes decreased with the increasing irradiation dose beginning at 1Gy and showed dose dependent reduction. From 12 to 72 hours after WBI with 4 Gy X rays TfR positive splenocytes started reducing at 12 hours after WBI and reached the nadir values at 24 hours and 48 hours ( P<0.05,P<0.01) , and began to recover from 72 hours after WBI. Conclusion High dose ionizing radiation inhibits the TfR expression in splenocytes of mice and there is an obvious dose dependency. The decrease of TfR expression may be related to the inhibition of IL 2 production and IL 2 receptor expression in cells by radiation.