Tissue‐resident innate immunity in the lung

Summary The lung is a unique organ that must protect against inhaled pathogens and toxins, without mounting a disproportionate response against harmless particulate matter and without compromising its vital function. Tissue‐resident immune cells within the lung provide local immunity and protection from infection but are also responsible for causing disease when dysregulated. There is a growing appreciation of the importance of tissue‐resident memory T cells to lung immunity, but non‐recirculating, tissue‐resident, innate immune cells also exist. These cells provide the first line of defence against pulmonary infection and are essential for co‐ordinating the subsequent adaptive response. In this review, we discuss the main lung‐resident innate immune subsets and their functions in common pulmonary diseases, such as influenza, bacterial pneumonia, asthma and inflammatory disorders.