Invariant natural killer T cells in lung diseases

Invariant natural killer T ( i NKT) cells are a subset of T cells that are characterized by a restricted T-cell receptor (TCR) repertoire and a unique ability to recognize glycolipid antigens. These cells are found in all tissues, and evidence to date suggests that they play many immunological roles in both homeostasis and inflammatory conditions. The latter include lung inflammatory diseases such as asthma and infections: the roles of lung-resident i NKT cells in these diseases have been extensively researched. Here, we provide insights into the biology of i NKT cells in health and disease, with a particular focus on the role of pulmonary i NKT cells in airway inflammation and other lung diseases. Immunology: cellular gatekeepers of pulmonary inflammation A small subset of immune cells residing in the lung plays a pivotal part in governing the inflammatory response in a range of pulmonary disorders. Invariant natural killer T ( i NKT) cells monitor the blood vessels in the lung for infection or other sources of tissue damage, which cause the cells to release chemical signals that rally a broader immune response. Doo Hyun Chung of Seoul National University, South Korea, and colleagues review the complex role of i NKT cells in determining the severity and outcome of respiratory disorders ranging from flu to pulmonary fibrosis. Sometimes i NKT cells are protective, for example by helping to quell the damaging inflammatory response associated with pulmonary fibrosis. However, some studies suggest that i NKT cells can exacerbate certain forms of asthma, highlighting the complexity of their physiological function.