Morphology Changes in Human Lung Epithelial Cells After Exposure to Diesel Exhaust Micron Sub Particles (PM₁.₀) and Pollen Allergens

In the recent literature there has been an increased interest in the effects of particulate matter on the respiratory tract. The objective of this study was to use an in vitro model of type II lung epithelium (A549) to evaluate the cell ability to take up sub-micron PM(1.0) particles (PM(1.0)), Parietaria officinalis (ALL), and PM(1.0) + ALL together. Morphological analysis performed by Transmission Electron Microscope (TEM) showed that PM and ALL interacted with the cell surface, then penetrating into the cytoplasm. Each single treatment was able to point out a specific change in the morphology. The cells treated appear healthy and not apoptotic. The main effect was the increase of: multilamellar bodies, lysosomal enzymes, microvilli, and presence of vesicle/vacuoles containing particles. These observations demonstrate morphological and functional alterations related to the PM(1.0) and P. officinalis and confirm the induction of the inflammatory response in lung cells exposed to the inhalable particles.