Tak T, Hilvering B, Tesselaar K, Koenderman L
Department of Respiratory Medicine, University Medical Centre Utrecht, Utrecht, the Netherlands.
Department of Immunology, Laboratory of Translational Immunology, University Medical Centre Utrecht, Utrecht, the Netherlands.
Clin Exp Immunol. 2015 Nov;182(2):204-12. doi: 10.1111/cei.12676. Epub 2015 Sep 16.
Inflammatory phenotypes of asthma are associated with differences in disease characteristics. It is unknown whether these inflammatory phenotypes are reflected by the activation status of neutrophils in blood and sputum. We obtained peripheral blood and induced sputum from 21 asthma patients and stratified our samples based on sputum eosinophilia resulting in two groups (>3% eosinophils: n = 13, <3%: n = 8). Eosinophils and neutrophils from blood and sputum were analysed for expression of activation and degranulation markers by flow cytometry. Data were analysed by both classical, non-parametric statistics and a multi-dimensional approach, using principal component analysis (PCA). Patients with sputum eosinophilia were characterized by increased asthma control questionnaire (ACQ) scores and blood eosinophil counts. Both sputum neutrophils and eosinophils displayed an activated and degranulated phenotype compared to cells obtained from blood. Specifically, degranulation of all granule types was detected in sputum cells, combined with an increased expression of the activation markers (activated) Mac-1 (CD11b), programmed death ligand 1 (PD-L1) (CD274) and a decreased expression of CD62L. CD69 expression was only increased on sputum eosinophils. Surface marker expression of neutrophils was similar in the presence or absence of eosinophilia, either by single or multi-dimensional analysis. Sputum neutrophils were highly activated and degranulated irrespective of sputum eosinophilia. Therefore, we conclude that differences in granulocyte activation in sputum and/or blood are not associated with clinical differences in the two groups of asthma patients. The finding of PD-L1 expression on sputum granulocytes suggests an immunomodulatory role of these cells in the tissue.
哮喘的炎症表型与疾病特征的差异相关。目前尚不清楚这些炎症表型是否通过血液和痰液中中性粒细胞的激活状态得以体现。我们从21例哮喘患者获取了外周血和诱导痰，并根据痰液嗜酸性粒细胞增多情况将样本分层，分为两组（嗜酸性粒细胞>3%：n = 13，<3%：n = 8）。通过流式细胞术分析血液和痰液中的嗜酸性粒细胞和中性粒细胞的激活和脱颗粒标志物表达。数据采用经典的非参数统计和使用主成分分析（PCA）的多维方法进行分析。痰液嗜酸性粒细胞增多的患者表现为哮喘控制问卷（ACQ）评分和血液嗜酸性粒细胞计数增加。与从血液中获取的细胞相比，痰液中的中性粒细胞和嗜酸性粒细胞均表现出激活和脱颗粒的表型。具体而言，在痰液细胞中检测到所有颗粒类型的脱颗粒，同时激活标志物（活化的）Mac-1（CD11b）、程序性死亡配体1（PD-L1）（CD274）表达增加，CD62L表达降低。CD69表达仅在痰液嗜酸性粒细胞上增加。无论有无嗜酸性粒细胞增多，通过单维或多维分析，中性粒细胞的表面标志物表达均相似。无论痰液嗜酸性粒细胞增多情况如何，痰液中的中性粒细胞均高度激活和脱颗粒。因此，我们得出结论，痰液和/或血液中粒细胞激活的差异与两组哮喘患者的临床差异无关。痰液粒细胞上PD-L1表达的发现提示这些细胞在组织中具有免疫调节作用。
