Resident lung immune cells that help repair infection-damaged tissues are identified in a paper published online this week in Nature Immunology. These cells elicit a molecule called amphiregulin that can restore lung function after influenza virus infection.

David Artis, John Wherry, and their colleagues identify immune cells, called innate lymphoid cells, in the airways of mice. Flu-infected mice lacking these innate cells fail to maintain body temperature and exhibit poorer lung function, as determine by measuring blood oxygen. However, infusion of these innate cells or administration of amphiregulin to the lungs of infected mice normalizes lung function and body temperature, suggesting that the activation of these cells is central to tissue repair at lung surfaces.

The authors show similar innate helper cells are found in human airways, raising the prospect that activating these cells might likewise help promote lung tissue repair in humans.