Th1/Th17细胞在肺部感染中的作用

目的：观察Th1、Th17型细胞因子在肺部感染性疾病中的动态变化,深入探讨机体抵抗肺部感染的免疫机制,为肺部感染性疾病的特异性诊治提供实验依据。方法：收集临床肺部感染患者血清、外周血淋巴细胞样本,分别用ELISA方法检测血清中Th1型细胞因子（IFN-γ）及Th17型细胞因子白细胞介素-17（IL-17）的表达水平,用FACS检测外周血中CD4＋IFN-γ＋Th1及CD4＋IL-17＋Th17细胞的比例变化,同时用Realtime-PCR方法检测外周血中Th17型细胞因子IL-17在基因水平的表达变化。以上指标的检测均以临床公认的CRP水平的变化作为参考。结果：ELISA结果显示,肺部感染患者血清IFN-γ的水平较健康对照组显著升高,动态检测结果显示IFN-γ变化水平与反映临床疾病状态的CRP出现显著的相关性。而IL-17的表达在不同的疾病过程未出现显著的变化。FACS及Real-time-PCR结果均显示CD4＋IFN-γ＋Th1的活性变化与疾病状态相关,而CD4＋IL-17＋Th17细胞在肺部感染不同阶段未出现显著的变化。结论：相对于Th17细胞而言,Th1细胞在机体防御肺部感染的过程中发挥更为关键的作用。Th17细胞在该类感染性疾病中的作用尚需进一步探讨。

Roles of Th1 and Th17 cells in the disease process of pneumonia

Objective.. To investigate the kinetic expression of Thl and Th17 cytokines in the patients with pneu- monia, look for more specific strategies for diagnosis and treatment of pneumonia. Methods.. Plasma and peripheral lymphocytes were collected from patients suffering from pneumonia or healthy controls. Thl cytokine IFN-γ and Th17 cytokine IL-17 in plasma were determined by ELISA. The ratio of CD^4＋ IFN-γ＋ Th1 and CD4^＋IL-17 Th17 in plasma was determined with intracellular staining （FACS）. Finally the expression of IL-17 within peripheral lymphocytes was also examined at mRNA level by real-time PCR. Levels of CRP were also analyzed simultaneously. Results.. Compared with that of healthy controls, expression of IFN-γ were significantly up-regulated in patients with pneumonia （P〈0. 01）. Both ELISA and intracellular staining show the same tendency. However, the expression of IL-17 did not increase significantly. Real-time PCR also showed that IL-17 was not significantly upregulated at mRNA level. IFN-7 but not IL-17 showed positive correlation with the expression of CRP （P〈 0.01 ）. Conclusion： Thl but not Thl 7 cells might play important roles in host defense against pneumonia. Roles of Th17 cells in this kind of infectious disease remain to be determined.