Abstract
Rationale: Recent research in murine models suggests an important role of Interleukin-1 receptor 1 (IL-1R1) signalling in the pathogenesis of COPD. Yet, the features of IL-1R1 expression in human COPD patients remain poorly investigated. This study characterizes the expression of IL-1R1 in lung tissues from COPD patients and control subjects.
Methods: Lung resections were obtained from 27 COPD patients; GOLD I (n=6), GOLD II-III (n=13) and GOLD IV (n=8). Never smoking controls (n=7) and smoking controls (n=6) served as controls. IL-1R1 expression was studied by immunohistochemistry and computerized image analysis. A double staining immunofluorescence protocol visualized IL-1R1 expressing cell populations.
Results: The expression of IL-1R1 in small airway epithelium was significantly higher in GOLD IV vs. GOLD II-III patients (p=0.03). In the small airway lamina propria, there was no overall statistical difference between the groups (p=0.12), but there was a tendency towards a higher IL-1R1 expression in GOLD IV vs. GOLD II-III patients (uncorrected p=0.02). In the endothelium, IL-1R1 expression was similar between the groups (overall p=0.8). IL-1R1 was found to be expressed on multiple leukocyte populations such as T-cells, dendritic cells, macrophages and NK-cells.
Conclusions: Our data suggest that at baseline conditions IL-1R1 is expressed in the airway epithelium, endothelial cells, and on multiple subepithelial leukocyte populations. Severe stages of COPD appear to be associated with increased IL-1R1 expression in small airway epithelium and in infiltrating cells in the lamina propria, a phenomenon that may participate in the abnormal immune reactions in advanced COPD.
- © 2011 ERS
