不同剂量电离辐射对小鼠脾脏调节性T细胞及TGF-β1表达的影响  

Effects of ionizing radiation with different doses on regulatory T cells and expression of TGF-β1 in mouse spleen

作　　者：孟凡旭[1] 单玉兴[2] 董娟聪[1] 金顺子[1] 

机构地区：[1]吉林大学公共卫生学院卫生部放射生物学重点实验室,吉林长春130021 [2]吉林大学第一医院骨科,吉林长春130021

出　　处：《吉林大学学报（医学版）》2011年第3期398-402,共5页Journal of Jilin University：Medicine Edition

基　　金：国家自然科学基金资助课题(30870584)

摘　　要：目的:观察不同剂量X射线照射后小鼠脾脏调节性T细胞(Treg)和转化生长因子-β1(TGFβ-1)表达的变化,探讨X射线对Treg阳性率及TGF-β1表达水平的影响。方法:雄性ICR小鼠,用X.S.S.205(FZ)型固定式X射线深部治疗机进行不同剂量的全身照射(低剂量组为0.050、0.075、0.100和0.200 Gy;高剂量组为0.500、1.000、2.000、4.000和6.000 Gy),同时设立假照组,于照射后16 h处死小鼠,取脾脏,分别采用流式细胞术、RT-PCR及Western blotting法检测Treg和TGFβ-1的表达水平。结果:与假照组比较,低剂量照射组小鼠脾脏Treg阳性率无明显变化(P>0.05);高剂量照射组,1.000 Gy照射后开始脾脏Treg阳性率明显高于假照组(P<0.05,P<0.01),并呈剂量依赖性升高。与假照组比较,小鼠脾脏细胞TGFβ-1 mRNA表达水平从0.500 Gy剂量组开始升高,2.000 Gy组达到假照组的2倍以上,但随后略有下降;在低剂量照射范围时,0.100 Gy组小鼠TGFβ-1蛋白表达水平明显高于假照组(P<0.05),而在大剂量组呈递增趋势,4.000 Gy和6.000 Gy组与假照组比较差异有统计学意义(P<0.05)。结论:在高剂量X射线诱导下小鼠脾脏Treg阳性率增高,同时TGFβ-1分泌增加,这种变化可能是高、低剂量X射线诱导不同免疫效应的又一原因。Objective To observe the changes of the regulatory T cells（Treg）and the expression of TGF-β1 in mouse spleen induced by different doses of X-ray irradiation at different time and study the effects of the X-ray on the Treg and TGF-β1.Methods The male ICR mice were irradiated with different doses of X-ray（low dose：0,0.050 Gy,0.075 Gy,0.100 Gy,0.200 Gy;high dose： 0,0.500 Gy,1.000 Gy,2.000 Gy,4.000 Gy,6.000 Gy） respectively by the XSS205（FZ）-type stationary X-ray deep therapy machine all over the body.Then the mice were killed 16 h after irradiation and the Treg and the expression level of TGF-β1 in the mouse spleen were detected by flow cytometry,RT-PCR and Western blotting.Results Compared with sham-irradiation group,the percentage of Treg had no significant changes in mouse spleen in low dose irradiation groups（P0.05）;in high dose irradiation groups,the percentage of Treg was increased as the dose rose from 1.000 Gy to the higher levels（P 0.05,P 0.01）,which showing a dose-dependent phenomenon.Compared with sham-irradiaton group,the level of TGF-β1 mRNA in mouse spleen had a trend to increase sustainedly as the dose was increased from 0.500 Gy to the higher doses,and then was increased to 2.000 times higher in 2 Gy group,following with a slight decrease.The level of TGF-β1 protein in mouse spleen in 0.100 Gy group was significantly higher than that in sham-irradiation group,and had an increasing tendency in high dose irradiation groups.There were significantly differences of the expression of TGF-β1 protein between 4.000 Gy group,6.000 Gy group and sham-irriadiation group（P0.05）.Conclusion The percentage of Treg is increased after induced by high dose X-ray,as well as the increasing secretion of the TGF-β1,which might be another reason for high and low dose X-rays inducing different immune responses.

关 键 词：电离辐射 调节性T细胞 转化生长因子 免疫效应 

分 类 号：R332[医药卫生—人体生理学] Q691[医药卫生—基础医学]