Innate lymphoid cells in the airways

The airways, similar to other mucosal surfaces, are continuously exposed to the outside environment and a barrage of antigens, allergens, and microorganisms. Of critical importance therefore is the ability to mount rapid and effective immune responses to control commensal and pathogenic microbes, while simultaneously limiting the extent of these responses to prevent immune pathology and chronic inflammation. The function of the adaptive immune response in controlling these processes at mucosal surfaces has been well documented but the important role of the innate immune system, particularly the recently identified family of innate lymphoid cells, has only lately become apparent. In this review, we give an overview of the innate lymphoid cells that exist in the airways and examine the evidence pertaining to their emerging roles in airways immunity, inflammation, and homeostasis.