低剂量X射线全身照射后小鼠IL-10和 IL-12的反向变化

通过检测低剂量辐射(LDR)对小鼠脾淋巴细胞中IL-10以及腹腔巨噬细胞中IL-12的影响,研究 LDR 辐射免疫效应的机制.采用 Northern blot 检测了75 mGy X 射线全身照射后, IL-10、IL-12 mRNA水平的变化,同时分别通过流式细胞术和ELISA检测了IL-10、IL-12 蛋白水平的变化. (1)Northern blot检测表明,75 mGy X射线全身照射后脾细胞中IL-10 的mRNA转录水平从照射后1 h即降低,并维持较低水平,一直到48 h开始恢复,达到假照射水平的86.2%;巨噬细胞中IL-12两亚基的mRNA水平的变化则表现为,照射后1h p35及p40亚基均迅速升高分别达到假照射组的131%和192%.而后,p35开始回降,直至照射后16-48 h恢复正常,p40亚基从照射后1-48h总体表现为升高. (2)对蛋白产物检测结果表明,脾细胞IL-10合成在照射后2 h开始即呈时间依赖性降低,至48 h仍无恢复迹象(p<0.01),双抗体夹心酶联免疫吸附法(ELISA)检测表明,巨噬细胞分泌IL-12明显增高.LDR引起IL-10和IL-12发生反向变化的结果为低剂量辐射增强细胞免疫功能提供了分子水平的实验依据.

CHANGES IN OPPOSITE DIRECTIONS FOR THE EXPRESSION OF IL-10 AND IL-12 AFTER LOW DOSE IRRADIATION

To observe the effects of LDR on the synthesis of IL-10 in splenocytes and the secretion of IL-12 by peritoneal macrophages. Northern blot and flow cytometry were adopted to detect the changes of IL-10 at mRNA and protein level, respectively. Northern blot and ELISA were used respectively to examine the changes of IL-12p35/p40 mRNA and IL-12p70 protein levels. In splenocytes IL-10 mRNA decreased significantly, while both IL-12 p35 and p40 subunits in macrophages increased after WBI with 75 mGy X rays. Meanwhile, IL-10 synthesis in splenocytes decreased beginning from 4h after exposure and remaining at low level up to 48h, and IL-12 secretion by macrophages was found to take an opposite direction. WBI with 75mGy X rays may suppress IL-10 both at the mRNA level and protein level and stimulate IL-12 expression simultaneously, and this would lead to a shift of the immune response in favour of T H 1 differentiation.