脓毒症小鼠不同组织炎症因子及T细胞亚群动态变化

目的 探讨CLP小鼠在脓毒症发病过程中不同脏器炎症浸润程度的变化以及不同免疫器官中T细胞亚群的相互关系。方法 对小鼠进行盲肠结扎穿孔术建立脓毒症模型，在术后0h、6h、12h、24h、48h及72h不同时间点检测小鼠血液、肺组织及回肠组织中IL-6、IL-10、IL-2、IL-4的含量变化，并以流式细胞技术检测小鼠脾脏中Treg及Th17比例变化、回肠黏膜固有层中CD4+T及CD8+T淋巴细胞比例变化。结果 肺组织及回肠组织中IL-6含量于术后6h达到峰值，血浆中IL-6含量于术后12h达到峰值，均显著高于同时间点假手术组（P＜0.01）。回肠组织中IL-10含量于术后6h达到峰值，明显高于假手术组（P＜0.01）。回肠组织中IL-2含量与术后出现持续上升，并在术后24h达到峰值，显著高于假手术组（P＜0.01）。血液、肺组织及回肠组织中IL-6、IL-10、IL-2、IL-4均于24h后大幅下降。CLP术后6h及24h的脾脏淋巴细胞Th17、Treg比例明显高于同时间点假手术组（P＜0.01）。回肠黏膜固有层中CD4+T细胞比例于术后12h达到最高，CD8+T细胞比例于术后24h达到最高，均显著高于假手术组（P＜0.01）。Th17、Treg、CD4+T及CD8+T细胞均于24h后出现下降。结论 脓毒症发病过程中，不同部位的炎症因子浸润程度不同，肠道黏膜中炎症反应出现最早且持续时间更长。脓毒症中后期CD8+T细胞的显著减少及Treg比例的相对性增加可能提示淋巴细胞增殖能力的下降。

Dynamic changes of inflammatory factors and T cell subsets in different tissues in septic mice

The purpose of this study is to investigate the changes of inflammatory infiltration degree in different organs and the relationship of T cell subsets in different immune organs in CLP mice during sepsis. Mice were treated with cecal ligation and perforation to establish sepsis model, and the levels of IL-6, IL-10, IL-2 and IL-4 in blood, lung and ileum were detected at 0h, 6h, 12h, 24h, 48h and 72h after operation. The percentage of Treg and Th17 in spleen and the proportion of CD4+T and CD8+T lymphocytes in lamina propria of ileum mucosa were detected by flow cytometry.?Data showed that the levels of IL-6 in lung and ileum reached the peak at 6h after operation, and the levels of IL-6 in plasma reached the peak at 12h after operation, which were significantly higher than those in sham group at the same time point (P < 0.01).?The levels of IL-10 in ileum reached the peak at 6h after operation, which was significantly higher than that in sham group (P < 0.01).?The level of IL-2 in ileum tissue increased continuously after operation, and reached the peak at 24h, which was significantly higher than that in sham group (P < 0.01).?The levels of IL-6, IL-10, IL-2 and IL-4 in blood, lung and ileum were significantly decreased after 24h.?The percentage of Th17 and Treg in spleen at 6h and 24h after CLP was significantly higher than that in sham group at the same time point (P < 0.01).?The percentage of CD4+T cells in lamina propria of ileum mucosa reached the highest at 12h after operation, and that of CD8+T cells reached the highest at 24h after operation, which were significantly higher than those in sham group (P < 0.01).?The percentage of Th17, Treg, CD4+T cells and CD8+T cells all decreased after 24h.?These data reveal that during the onset of sepsis, inflammatory factors in blood and different tissues have different infiltration degrees, and the inflammatory reactions in intestinal mucosa appear earliest and last longer. The significant decrease of CD8+T cells and relative increase of the percentage of Treg in the middle and late stage of sepsis may indicate a decrease in lymphocyte proliferation ability.