title: Type 1 pulmonary epithelial cells: a new compartment involved in the slow phase of particle clearance from alveoli.
abstract: Whilst alveolar macrophages normally clear micron-sized particles from the respiratory units, nanoparticles might by-pass this mechanism and interact with alveolar epithelium. This letter discusses the possible role of alveolar epithelial type 1 cells in uptake and retention of nanoparticles within the alveolar septum. Accelerated apoptosis of nanoparticle-laden type 1 cells might trigger pro-inflammatory responses during apoptotic cell removal by macrophages. In the absence of clearance of apoptotic type 1 cells by this route, release of nanoparticles by dead type 1 cells and continued retention within the alveolar septum could lead to a slow process of nanoparticle removel from within the alveolar septum, rather than surface-only clearance. We suggest that this hypothesis warrants further research.
authors.affiliation: Southcott, Parkham Ash, Bideford, Devon, UK. robertmaynard3@gmail.com
authors.forename: Robert L
authors.initials: RL
authors.lastname: Maynard
authors.forename: Kenneth
authors.initials: K
authors.lastname: Donaldson
authors.forename: Teresa D
authors.initials: TD
authors.lastname: Tetley
mesh_terms: D017209:Apoptosis; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D053758:Nanoparticles; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000166:cytology* / Q000378:metabolism*; D014116:Toxicology