Figure 1.

General mechanisms damaging pulmonary barrier. Infection via pathogen-associated molecular pattern (PAMPs) or damage-associated molecular pattern (DAMPs), the latter released due to physical damage of pneumocytes, activates alveolar macrophages (AMs) and later other immune cells migrating into alveoli. Excessive activation of AMs leads to the development of lung injury due to excessive generation of reactive oxygen and/or nitrogen species (RONS), cytokine storm and pro-coagulant activity.