小鼠外周血免疫相关细胞的近日节律性研究

Research on the circadian rhythm of immune cells in the peripheral blood in mice

目的研究小鼠外周血中相关免疫细胞的近日节律性变化。方法将雄性C57 BL/6小鼠置于12 h明∶12 h暗(12 h L∶12 h D)的光暗循环条件下饲养4周,在1昼夜24 h的4个时间点(9∶00,15∶00,21∶00,3∶00)取外周血,分别用血细胞记数仪检测外周血相关的免疫细胞,包括白细胞总数、淋巴细胞数、CD4+淋巴细胞百分比、CD8+淋巴细胞百分比、单核细胞及中性粒细胞百分比等。结果在12 h L∶12 h D的光暗循环条件下,小鼠外周血的相关免疫细胞存在近日节律性变化特征,但峰值和谷值各不相同。白细胞总数在15∶00达到高峰[(9.1±1.8)×109/L],各类淋巴细胞(CD4+和CD8+)的峰值均在15∶00-21∶00,单核细胞数在15∶00达到高峰(0.487×109/L),中性粒细胞数在3∶00达到高峰(0.127×109/L)。结论在12 h L∶12 h D的光暗循环条件下,小鼠外周血中各免疫细胞存在此消彼长的现象,以此来维持总体免疫系统的平衡。

Objective To research the circadian rhythm of immune cells in the peripheral blood in mice. Methods C57 BL/6 male mice were kept in the standardized light-dark cycle （12 h L： 12 h D） for 4 weeks. Then, peripheral blood samples were collected at 4 time points （9：00, 15：00, 21：00 and 3：00 ）. Flow eytometry was used to detect immune cells, including the total number of white blood cells, the number of lymphocytes, the percentage of CD4^＋ lymphocytes, the percentage of CD8^＋ lymphocytes, the number of monocytes and the percentage of granulocytes. Results In the standardized light-dark cycle, the immune cells in the peripheral blood exhibited a significant circadian rhythm with different apex and nadir. The white blood cells reached apex[（9.1 ＋ 1.8）×10^9/L] at 15：00 hours, various lymphocytes （CD4^＋ lymphocytes and CD8 ＋ lymphocytes） reached apex from 15：00 to 21：00 hours. The number of mononuclear ceils reached apex（0.487×10^9/L） at 15：00 hours, while the number of granulocytes reached apex（0. 127×10^9/L） at 3：00 hours. Conclusion In the light-dark cycle, the immune components fluctuated for maintaining the balance of the immune system.