Genetic characterization of macrophages from induced sputum of asthma and COPD patients

Background: Macrophages are important cells in pathogenesis of obstructive lung diseases including asthma and chronic obstructive pulmonary disease (COPD). The aim of the study was a multivariate, genetic, comparative analysis of macrophages from patients with asthma and COPD. Methods: Macrophages were isolated from induced sputum (IS) by magnetic bead separation. Transcriptomic measurements were carried out using Affymetrix Human Gene 2.1 ST ArrayStrip in 17 samples: 8 asthma (4 ICS naive , 4 ICS treated), 4 COPD and 5 control samples. The expression of the most significantly differentiating genes was evaluated by real time PCR in 34 samples (15 patients with asthma, 11 patients with COPD and 17 controls). Results: USP53 was the only gene differentially expressed (p adjusted clue =0.09) in the comparison between ICS naïve and ICS treated asthma. The PCR verification showed increased expression of BTF3, CDS2, DNAJC13, DDX5, GNAI2, SCGB1A1, SIRPB1, TRAF3IP, USP53, WDR49 in the asthma compared to COPD group. The changed gene expression profile of macrophages were characterized mostly by gene ontology terms linked with cell motility, cilium function, cell junction and adhesion organization. Conclusions: Gene expression profiling of sputum macrophages revealed distinct molecular capacity in asthma and COPD. The role of sputum macrophages in the pathophysiology of obstructive lung diseases is probably connected with biological processes associated with their motility, cilium dysfunction and cell junction organization. The microarray experiments were performed using 17 samples: 8 asthma (4 untreated , 4 treated with ICS), 4 COPD and 5 control samples (4 non-smoker, 1 smoker)