中文摘要：

目的观察不同剂量X射线照射后小鼠脾细胞可诱导共刺激分子及其配体（ICOS／ICOSL）与核因子NF—KB、细胞因子IL-10表达量的变化。方法健康ICR小鼠按随机数字表法分为低剂量照射组（0．05、0．075和0．2Gy）、高剂量照射组（1、2、4和6Gy）和假照组。假照组于假照后16h处死，高、低剂量照射组分别于照后0、4、8、16、24、48、72h处死小鼠，分离小鼠脾脏制成单细胞悬液，提取脾组织总蛋白，采用流式细胞术检测ICOS／ICOSL，Westernblot法检测NF—KB蛋白水平，采用ELISA法检测IL-10分泌量的变化。结果在0．05、0．075Gy低剂量照射后，ICOS／ICOSL双阳性细胞百分比显著低于假照组（t=4．743、4．120，P〈0．01）；在4、6Gy高剂量照射后，则上调其表达（t=-4．950、-7．310，P〈0．01）。核因子NF-KB变化趋势与ICOS／ICOSL表达变化相似。IL-10在0．075、0．2Gy低剂量照射后明显低于假照组（t=5．277、2．854，P〈0．05），但在6Gy照射后明显高于假照组（t=7．196，P〈0．01）。结论低剂量电离辐射抑制ICOS／ICOSL、NF—KB和IL-10的表达，而高剂量辐射上调ICOS／ICOSL表达，并激活核因子NF-KB，进而导致IL-10分泌量升高。

英文摘要：

Objective To observe the changes of inducible co-stimulator and ligand （ICOS! ICOSL）, nuclear factor NF-kB, and cytokine IL-10 in mouse spleen after different doses of ionizing radiation. Methods The healthy ICR mice were randomly divided into low dose irradiation groups with 0.05, 0. 075 and 0.2 Gy and high dose irradiation groups with 1,2, 4 and 6 Gy, respectively. The control mice were killed 16 h after sham-irradiation and the irradiated mice were killed at 0, 4, 8, 16, 24, 48, 72 h after irradiation. Mice spleen was taken out to prepare for single cell suspension and to extract total protein. The expression of ICOS/ICOSL was detected using flow cytometry. The expressions of NF-KB and IL-10 were detected by Western blot and ELISA, respectively. Results After low doses of 0.05 and 0. 075 Gy, the percentage of ICOS/ICOSL double positive cells was significantly lower than that of sham- irradiation （t = 4. 743, 4. 120 ,P 〈 0.01 ）. The expression of ICOS/ICOSL was increased after high doses of 4 and 6 Gy irradiation （t = -4.950, -7.310,P 〈0.01）. The NF-KB expression had a similar tendency with ICOS/ICOSL. But the secretion of IL-10 was decreased after low dose of 0. 075 and 0.2 Gy irradiation （t = 5. 277, 2. 854, P 〈 0.05 ） , but increased after 6 Gy irradiation compared with sham- irradiation group （t = 7. 196, P 〈 0. 01 ）. Conclusions Low dose irradiation inhibits the expressions of ICOS/ICOSL, NF-kB and IL-10 ,while high dose irradiation inscreases the expression of ICOS/ICOSL and activates NF-kB then increases the secretion of IL-10.