Flagellin shifts 3D bronchospheres towards mucus hyperproduction

• Published in: Respiratory research Vol. 21; no. 1; pp. 1 - 222
• Main Authors: Sprott, Richard F, Ritzmann, Felix, Langer, Frank, Yao, Yiwen, Herr, Christian, Kohl, Yvonne, Tschernig, Thomas, Bals, Robert, Beisswenger, Christoph
• Format: Journal Article
• Language: English
• Published: London BioMed Central Ltd 26.08.2020; BioMed Central; BMC
• Subjects: Antibodies; Bacteria; Bacterial diseases; Bacterial infections; Basal cells; Bronchospheres; Cell differentiation; Chronic obstructive pulmonary disease; Cilia; Cystic fibrosis; Cytokines; Development and progression; Differentiation; Epithelial cells; Epithelium; Flagellin; Fluorescence; Fluorescence microscopy; Genetic aspects; Globular proteins; Goblet cells; Health aspects; Hyperplasia; Infections; Inflammation; Letter to the Editor; Lung diseases; Microscopy; Mucus; Obstructive lung disease; Organoids; PAMPs; Properties; Respiratory diseases; Respiratory tract; Respiratory tract diseases; Software; TLR2 protein; Toll-like receptors; Germany; United States > US
• ISSN: 1465-993X; 1465-9921; 1465-993X; 1465-9921
• DOI: 10.1186/s12931-020-01486-x

Abstract Cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) are associated with acute and chronic bacterial infections of the lung. Excessive differentiation of basal cells to mucus-producing goblet cells can result in mucus hyperproduction and loss of mucociliary clearance in the airways of CF and COPD patients. Here, we aimed to investigate the effect of pathogen-associated molecular patterns (PAMPs) on the differentiation of human 3D bronchospheres. Primary human bronchial epithelial cells (HBECs) were differentiated to bronchospheres in the presence of bacterial flagellin and LPS and the synthetic Toll-like receptor (TLR) ligands Pam3CSK4 (TLR-2) and polyinosinic:polycytidylic acid (pIC, TLR-3). Electron and fluorescence microscopy showed that the differentiation of bronchospheres associated with the formation of lumina and appearance of cilia within 30 days after seeding. Incubation with flagellin resulted in a decreased formation of lumina and loss of cilia formation. Incubation with Pam3CSK, pIC, and LPS did not significantly affect formation of lumina and ciliation. Mucus production was strongly increased in response to flagellin and, to a lesser degree, in response to Pam3CSK4. Our results indicate that bacterial factors, such as flagellin, drive the differentiation of the respiratory epithelium towards mucus hyperproduction.