The Importance of Lung Innate Immunity During Health and Disease

The lung is a vital organ for the body as the main source of oxygen input. Importantly, it is also an internal organ that has direct contact with the outside world. Innate immunity is a vital protective system in various organs, whereas, in the case of the lung, it helps maintain a healthy, functioning cellular and molecular environment and prevents any overt damage caused by pathogens or other inflammatory processes. Disturbances in lung innate immunity properties and processes, whether over-responsiveness of the process triggered by innate immunity or lack of responses due to dysfunctions in the immune cells that make up the innate immunity system of the lung, could be correlated to various pathological conditions. In this review, we discuss globally how the components of lung innate immunity are important not only for maintaining lung homeostasis but also during the pathophysiology of notable lung diseases beyond acute pulmonary infections, including chronic obstructive pulmonary disease (COPD), asthma, and pulmonary fibrosis.