γ射线胸部照射小鼠早期肺组织的免疫细胞反应

目的 探索γ射线胸部照射小鼠早期肺组织免疫相关T淋巴细胞反应。 方法 将112只C57BL/6 雄性小鼠6~8 周龄，（20±2） g]采用随机数字表法随机分为14组（照射组和对照组各7组），每组8只。照射组小鼠进行单次20 Gy 60Co γ射线胸部照射，分别在照射后第3 、12 小时和第1 、2 、3 、7 、14 天用流式细胞仪检测肺组织的白细胞、T淋巴细胞（CD3+）及其CD4+和CD8+亚群、调节性T细胞（Treg）等免疫细胞比例的变化。两组间比较采用 t 检验。 结果 照射后的小鼠肺组织白细胞显著降低（t=3.446~7.781，均P<0.01）；CD3+T细胞在照射后早期（第3小时至第2天）降低明显（t=4.413~15.430，均P<0.01）；Treg （CD4+CD25+Foxp3+）显著升高（t=2.813~4.406，均P<0.05）；CD4+在照射后早期（第3小时和第12小时）减少（t=5.019、4.912，均P<0.01），1 d后恢复至对照组水平；CD8+在照射后早期（第3小时和第12小时）无明显变化，第1天和第3天降低明显（t=6.736、4.738，均P<0.01），第7 天后升高（t=7.537、3.903，均P<0.01）；CD4+/CD8+比值在照射后12 h内降低（t=5.624、4.083，均P<0.01），第1天和第3天升高明显（t=13.410、5.702，均P<0.01），但7 d后又下降（t=5.505、3.928，均P<0.01）。 结论 胸部照射小鼠早期肺组织免疫相关细胞呈现各种不同变化，这可能与辐射导致免疫细胞损伤以及机体应激反应产生的免疫应答有关。

Early response of immune-related T cells in the lung tissue of mice exposed to gamma rays in the chest

Objective To explore the early response of immune-related T cells in the lung tissue of mice, whose chests were exposed to gamma rays. Methods A total of 112 C57BL/6 mice (6–8 weeks old, (20 ± 2) g) were randomly divided into 14 groups (7 irradiation groups and 7 corresponding control groups, n = 8). The irradiation groups received a single dose of chest irradiation (20 Gy) by using a 60Co ray source. The immune cells in the lung, including white blood cells and T cell (CD3+) and its subtypes (CD4+/CD8+/Treg) in the lung tissue, were detected using flow cytometry at 3 h, 12 h, and 1, 2, 3, 7, and 14 days after irradiation. The t test was used to compare the two groups. Results The leukocytes in the lung tissue of irradiated mice were significantly reduced (t=3.446–7.781, all P<0.01). The CD3+ T cells decreased early after irradiation (3 h–2 days; t=4.413–15.430, all P<0.01). The Treg cells (CD4+CD25+Foxp3+) increased significantly (t=2.813–4.406, all P<0.05). The CD4+ T cells decreased significantly at the early stage after irradiation (3 h and 12 h; t=5.019, 4.912; both P<0.01) and returned to the control level after one day. The CD8+ T cells did not change at the early stage (3 h and 12 h), decreased significantly at 1 and 3 days ( t=6.736, 4.738; both P<0.01), and increased significantly after seven days (t=7.537, 3.903; both P<0.01). The CD4+/CD8+ ratio decreased within 12 h after irradiation ( t=5.624, 4..083; both P<0.01), increased significantly at 1 and 3 days (t=13.410, 5.702; both P<0.01), and decreased again after seven days (t=5.505, 3.928; both P<0.01). Conclusion Chest-irradiated mice showed different changes in immune-related cells in the lung tissue at the early stage after irradiation, which may be related to the damage of immune cells by radiation and the immune response produced by the body's stress response.