Lung Macrophage Phenotypes and Functional Responses: Role in the Pathogenesis of COPD

• Published in: International journal of molecular sciences Vol. 19; no. 2; p. 582
• Main Authors: Yamasaki, Kei, Eeden, Stephan F van
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 15.02.2018; MDPI
• Subjects: Adaptive immunity; Adaptive Immunity - immunology; Chronic obstructive pulmonary disease; Disease; Effector cells; Fungi; Humans; Immune response; Immunity, Innate - immunology; Inflammation - immunology; Inflammation - pathology; Lung - immunology; Lung - pathology; Lung diseases; lung macrophage phenotypes; Macrophages; Macrophages, Alveolar - immunology; Macrophages, Alveolar - pathology; Monocytes; Monocytes - immunology; Obstructive lung disease; Organs; Particulate matter; Pathogenesis; phagocytic function of macrophage; Phagocytosis; Phagocytosis - immunology; Phenotypes; Pulmonary Disease, Chronic Obstructive - immunology; Pulmonary Disease, Chronic Obstructive - pathology; Review; Smoking - adverse effects; Therapeutic applications; phagocytic function of macrophage; lung macrophage phenotypes; chronic obstructive pulmonary disease
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms19020582

Lung macrophages (LMs) are essential immune effector cells that are pivotal in both innate and adaptive immune responses to inhaled foreign matter. They either reside within the airways and lung tissues (from early life) or are derived from blood monocytes. Similar to macrophages in other organs and tissues, LMs have natural plasticity and can change phenotype and function depending largely on the microenvironment they reside in. Phenotype changes in lung tissue macrophages have been implicated in chronic inflammatory responses and disease progression of various chronic lung diseases, including Chronic Obstructive Pulmonary Disease (COPD). LMs have a wide variety of functional properties that include phagocytosis (inorganic particulate matter and organic particles, such as viruses/bacteria/fungi), the processing of phagocytosed material, and the production of signaling mediators. Functioning as janitors of the airways, they also play a key role in removing dead and dying cells, as well as cell debris (efferocytic functions). We herein review changes in LM phenotypes during chronic lung disease, focusing on COPD, as well as changes in their functional properties as a result of such shifts. Targeting molecular pathways involved in LM phenotypic shifts could potentially allow for future targeted therapeutic interventions in several diseases, such as COPD.