Inhibition of IL-4Rα reduces CCL26 in bronchial epithelial cells from COPD patients.

BACKGROUND: Anti-interleukin (IL)-4Rα monoclonal antibodies (mAb) improve lung function and decrease the number of exacerbations in patients with COPD type (T)2 inflammation. However, the involvement of early innate immune responses underlying these treatment effects is not well known. We sought to understand the effect and mechanisms of IL-4Rα mAb treatment on bronchial epithelial cells (BECs) from COPD patients under T2 inflammatory conditions with and without rhinoviral infection. METHODS: Primary BECs from healthy and COPD patients were grown at an air-liquid interface and stimulated with IL-4 or IL-13 cytokines in the presence of IL-4Rα mAb. Cells were infected with human rhinovirus 1B and collected 24†h after infection. Antiviral mediators (i.e., interferons (IFNs) and pattern recognition receptors (PRRs)), as well as chemokine and alarmin expression, were measured by reverse transcriptase quantitative PCR and ELISA. RESULTS: Treatment with IL-4Rα mAb (100 nM) inhibited the eotaxin-3 (CCL26) gene after IL-4/IL-13 induction (p<0.05) in COPD BECs. However, no significant changes in rhinovirus-induced IFN-β, PRRs or thymic stromal lymphopoietin gene responses were observed with IL-4/IL-13 stimulation and IL-4Rα mAb treatment. A significant increase in mucin 5AC gene expression was observed with both IL-4 and IL-13 stimulation, but it was not reduced with IL-4Rα treatment in BECs. CONCLUSIONS: Inhibition of IL-4Rα reduced CCL26 levels without affecting antiviral immune responses in BECs from COPD patients. Inhibition of IL-4Rα reduced IL-4/IL-13 signalling without broadly suppressing the immune system, which might suggest that inhibition of the IL-4Rα pathways may prevent COPD exacerbations through reduction of eosinophil chemotaxis.