Cellular network in airways inflammation and remodelling.

Chronic inflammation and airway remodelling are two key steps in asthma pathophysiology. The development of chronic airway inflammation depends upon the continuous recruitment of inflammatory cells from the bloodstream towards the bronchial mucosa and by their subsequent functional activation. The release of inflammatory mediators by activated cells contributes to the generation of a complex network which involves mobile inflammatory cells and structural cells such as epithelial cells, fibroblasts and myofibroblasts. This network is responsible for the amplification and persistence of the inflammatory process as well as for the development of a peculiar microenvironment which can directly modulate the survival of inflammatory cells in the inflamed airways. Increased cellular recruitment and activation, enhanced cell survival and cell:cell interactions are therefore the key steps in the development of chronic airway inflammation in asthma and represent the major causes for tissue damage, repair and remodelling.