The airway epithelium: more than just a structural barrier.

TitleThe airway epithelium: more than just a structural barrier.
Publication TypeJournal Article
Year of Publication2011
AuthorsTam, A, Wadsworth, S, Dorscheid, D, Man, SFPaul, Sin, DD
JournalTher Adv Respir Dis
Volume5
Issue4
Pagination255-73
Date Published2011 Aug
ISSN1753-4666
KeywordsAnimals, Basement Membrane, Bronchi, Cell Communication, Cell Movement, Epithelial Cells, Epithelium, Humans, Lung, Neutrophils, Pulmonary Alveoli, Tight Junctions
Abstract

The mammalian airway is lined by a variety of specialized epithelial cells that not only serve as a physical barrier but also respond to environment-induced damage through the release of biologically active factors and constant cellular renewal. The lung epithelium responds to environmental insults such as pathogens, cigarette smoke and pollution by secreting inflammatory mediators and antimicrobial peptides, and by recruiting immune cells to the site of infection or damage. When the epithelium is severely damaged, basal cells and Clara cells that have stem-cell-like properties are capable of self-renewal and proliferation in the affected area, to repair the damage. In order to effectively fight off infections, the epithelium requires the assistance of neutrophils recruited from the peripheral circulation through transendothelial followed by transepithelial migration events. Activated neutrophils migrate across the epithelium through a series of ligand-receptor interactions to the site of injury, where they secrete proteolytic enzymes and oxidative radicals for pathogen destruction. However, chronic activation and recruitment of neutrophils in airway diseases such as chronic obstructive pulmonary disease and asthma has been associated with tissue damage and disease severity. In this paper, we review the current understanding of the airway epithelial response to injury and its interaction with inflammatory cells, in particular the neutrophil.

DOI10.1177/1753465810396539
Alternate JournalTher Adv Respir Dis
PubMed ID21372121