Microscopic, submicroscopic characterization of pro- and anti-inflammatory cell phenotypes of the lungs in conditions of experimental allergic inflammation

Abstract

The aim is to study the microscopic and submicroscopic characteristics of pro- and anti-inflammatory cell phenotypes of the lungs under conditions of experimental allergic inflammation. Material and methods. We used histological and electron microscopic methods to study the lungs of 48 male guinea pigs in experimental ovalbumin-induced allergic inflammation, simulated by subcutaneous sensitization and subsequent intranasal inhalation with ovalbumin. Submicroscopic changes of respiratory endocrine cells, goblet cells, exocrine bronchiolar cells, mast cells, macrophages, eosinophils, endothelial cells of guinea pigs lungs were determined. Results. The most significant reactive submicroscopic changes were established on the 23rd and 30th days of observation in the form of an increase in the functional activity of exocrine bronchiolar and goblet cells, as evidenced by the presence of a light nucleus with a predominance of euchromatin, nucleoplasm of low electron-optical density, nucleoli, developed granular endoplasmic reticulum and an increase in the number of goblet cells secretory mucous granules by electron microscopic examination. The revealed ultramicroscopic features of respiratory endocrine cells (an increase in a number of “empty” core dense vesicles), eosinophilic granulocytes (piecemeal degranulation), an increase in the number of mast cells granules, numerous pseudopodia in macrophages are the confirmation of the active participation of these cell phenotypes in the initiation of inflammation during the early period of the allergic inflammatory process in lungs. Conclusions. A significant reaction of the innate nonspecific and adaptive immunity occurs in airways during the experimental ovalbumin-induced allergic inflammation, consisting primarily of the functional activation of eosinophilic granulocytes, mast cells, and macrophages, as well as an increase in the secretory activity of exocrine bronchiolar cells and goblet cells, which is confirmed by the changes investigated by electron microscopic examination and are accompanied by reactive changes in the vessels of microcirculatory bed.