Neutrophils from severe asthmatic patients induce epithelial to mesenchymal transition in healthy bronchial epithelial cells

Background Asthma is a heterogenous disease characterized by chronic inflammation and airwayremodeling. An increase in the severityof airwayremodeling is associated with a more severeform of asthma. There is increasing interest in the epithelial to mesenchymaltransition process and mechanisms involved in the differentiation and repair of the airwayepithelium, especially as they apply to severeasthma. Growing evidence suggests that Epithelial-Mesenchymal transition(EMT) could contribute to airwayremodeling and fibrosis in asthma. Severeasthmatic patients with remodeled airwayshave a neutrophil driven inflammation. Neutrophils are an important source of TGF-β1, which plays a role in recruitment and activation of inflammatory cells, extracellular matrix (ECM) production and fibrosis development, and is a potent inducer of EMT.