Type 1 pulmonary epithelial cells: a new compartment involved in the slow phase of particle clearance from alveoli.

Whilst alveolar macrophages normally clear micron-sized particles n from the respiratory units, nanoparticles might by-pass this t mechanism and interact with alveolar epithelium. This letter n discusses the possible role of alveolar epithelial type 1 cells in ii uptake and retention of nanoparticles within the alveolar septum. (1 Accelerated apoptosis of nanoparticle-laden type 1 cells might e trigger pro-inflammatory responses during apoptotic cell removal o by macrophages. In the absence of clearance of apoptotic type 1 p cells by this route, release of nanoparticles by dead type 1 cells si and continued retention within the alveolar septum could lead to ft a slow process of nanoparticle removel from within the alveolar ti septum, rather than surface-only clearance. We suggest that this li hypothesis warrants further research. [ABSTRACT FROM AUTHOR]