电离辐射对小鼠腹腔巨噬细胞TLR4和转接蛋白MyD88表达的影响

目的：观察电离辐射对小鼠腹腔巨噬细胞TLRs介导的信号传导通路中TLR4和转接蛋白MyD88表达的影响，探讨低剂量辐射诱导机体免疫效应的机制。方法：昆明系雄性小鼠160只。时间-效应实验60只，随机分为假照组、照射后4、8、16、24和48 h实验组，每组10只；剂量-效应实验100只，随机分为假照组、0.050、0.075、0.100、0.200、0.500、1.000、2.000、4.000和6.000 Gy照射组，每组10只；X 线全身照射 (WBI) 后，采用流式细胞术检测小鼠腹腔巨噬细胞中TLR4和MyD88阳性细胞百分率。结果：时间-效应实验表明，与假照组比较，0.075 Gy 照射后TLR4和MyD88表达率在4 h后开始增高，分别在16 h和4 h达高峰（P<0.05或P<0.01，）；2.000 Gy 照射后，TLR4和MyD88表达率在4 h后开始增高， 16 h达高峰（P<0.01）。剂量-效应实验表明，与假照组比较，各剂量照射组 TLR4和MyD88表达率均随照射剂的增加递增，在0.075 Gy 开始明显增加（P<0.05），在2.000 Gy 照射后达高峰（P<0.01）。结论：电离辐射使小鼠腹腔巨噬细胞TLR4和转接蛋白MyD88表达增高,促进小鼠的免疫反应，启动固有免疫及适应性免疫。

Effect of ionizing irradiation on expressions of TLR4 and adaptor protein MyD88 in peritoneal macrophages of mice

Objective To observe the effect of ionizing radiation on the expressions of TLR4 and adaptor protein MyD88 in mouse peritoneal macrophages in the Toll-mediated signal transduction pathways.Methods 160 male Kunming white mice were randomly divided into 16 groups(ten each group):sham-irradiation and five groups after 4,8,16,24 and 48 h X-ray irradiation for time-course experiments;sham-irradiation and nine groups after 0.05,0.075,0.100,0.200,0.500,1.000,2.000,4.000,6.000 Gy irradiation for dose-effect experiments.Flow cytometry was used to detect the expressions of TLR4 and MyD88 after whole body irradiation (WBI) with X-rays.Results Both of TLR4 and Myd88 expressed more than shamirradiation after 0.075 and 2.000 Gy WBI for 4 h,and the expressions of them reached the peak at 16 h or 4 h after WBI(P<0.05 or P<0.01) in time-course experiments.In dose-effect experiments,the expression levels of TLR4 and MyD88 increased gradually with the enhancement of X-rays irradiation dose,both of them reached the peak at 2.000 Gy WBI,and there was significant difference compared with sham-irradiation group(P<0.01).Conclusion X-ray irradiation can increase the expressions of TLR4 and MyD88 in mouse peritoneal macrophages,promote the immune respose and start the adaptive immunity of mice.