Characteristics and role of macrophages in pathogenesis of acute and chronic lung diseases

Macrophages are among the most abundant cells of the respiratory tract, being characterized by their ability to have different phenotypes, depending on signals from the microenvironment (classically activated M1, alternatively activated M2). Despite contradictory literature data describing role of various macrophage phenotypes, they appear to be coupled to the systems protecting the organism from infectious pathogens and preventing development of excessive tissue responses. Phenotypical changes of lung macrophages are found in various respiratory diseases including bronchial asthma, chronic obstructive pulmonary disease, pulmonary fibrosis and infectious conditions. In this review article, we focused on the biology, origin and characterization of different macrophage phenotypes, and presented current data highlighting their role in development of chronic lung diseases, i.e., bronchial asthma, chronic obstructive pulmonary disease and acute infectious diseases