part of part of macrophage lung macrophage Circulating macrophages and tissue macrophages (alveolar macrophages) of lung. lung macrophages Lung macrophages refer to macrophage populations in the lungs, including the tissue-resident alveolar macrophages and interstitial macrophages, located in the air spaces and the connective tissue of the lung, respectively, and recruited macrophages. They are important in maintaining tissue homeostasis and immunity. The primary function of lung macrophages is to patrol and maintain the pulmonary system, where they serve as the first line of defense against airborne pathogens and inhaled particles. They perform phagocytosis of pathogens, particulate matter, dead cells, and other cellular debris from the lungs to maintain clear air passages and optimize gas exchange. They may also participate in tissue repair and the resolution of inflammation following injury. Lung macrophages also play a critical role in immune regulation. They help to initiate an immune response by secreting cytokines and other inflammatory mediators and by presenting antigens from the pathogens they have engulfed to induce T cell responses. However, if activated improperly, lung macrophages can contribute to inflammatory diseases of the lung such as chronic obstructive pulmonary disease (COPD) or asthma. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) CALOHA:TS-0576 https://cellxgene.cziscience.com/cellguide/CL_1001603 lung