Although airway remodeling is well established to be present in asthma, the specific immune and inflammatory pathways leading to airway remodeling in human asthmatics are incompletely understood. “Severe Asthma Core B” will advance our understanding of the pathogenesis of airway remodeling in severe asthma by providing each of the project access to well characterized human lung bronchial brush, bronchial biopsy, bronchoalveolar lavage, and sputum specimens from severe asthma subjects (with varying levels of remodeling) and control subjects (mild asthma; non-asthma). This will allow individual Projects 1-3 to investigate whether the immune, inflammatory, and remodeling molecule/pathway they are studying is more highly expressed in severe asthma compared to control subjects, is more highly expressed in severe asthma compared to mild asthma, is more highly expressed in asthmatics with higher levels of remodeling, is expressed at levels that differ in lung airway anatomical compartments (i.e. proximal airway vs distal airway), and whether differences in expression levels are detectable in sputum to potentially use as a future biomarker of remodeling. Core B will also be a resource to provide well-characterized human severe asthma and control lung structural cells (epithelium, airway smooth muscle, fibroblast) and immune cells (tissueresident memory T cells or TRM) for study in each Project. Finally, Core B will allow investigators in each project to utilize a novel ex vivo human lung airway bronchodilation, bronchoconstriction, and airway remodeling assay to determine whether the pathway/cell type they are studying influences bronchodilation, bronchoconstriction, or airway remodeling in human lung airways from asthma compared to controls. Overall, the provision of these human lung and sputum specimens from severe asthma and control subjects will allow the individual projects to determine whether the defined inflammatory and remodeling pathways they are investigating are different in asthmatics with differing levels of severity, or differing levels of remodeling, as compared to control subjects.