What is the physiological function of mast cells?

TLDR

Mast cells are abundant in skin and mucosa, positioned near nerves, vessels, and hair follicles, and while historically linked to allergic responses, recent work shows they play diverse roles in normal tissue physiology. The paper seeks to map the expanding landscape of mast cell roles beyond allergic immunity. Recent work has uncovered a wide array of mast cell functions beyond allergic responses.

Abstract

Abstract: Under physiological conditions, skin mast cells preferentially localize around nerves, blood vessels and hair follicles. This observation, which dates back to Paul Ehrlich, intuitively suggests that these enigmatic, multifacetted protagonists of natural immunity are functionally relevant to many more aspects of tissue physiology than just to the generation of inflammatory and vasodilatory responses to IgE‐dependent environmental antigens. And yet, for decades, mainstream‐mast cell research has been dominated by a focus on the – undisputedly prominent and important – mast cell functions in type I immune responses and in the pathogenesis and management of allergic diseases. Certainly, it is hard to believe that the very large and rather selectively distributed number of mast cells in normal, uninflamed, non‐infected, non‐traumatized mammalian skin or mucosal tissue is simply hanging around there lazily day and night, just to wait for the odd allergen or parasite‐associated antigen to come by so the mast cell can finally swing into action. Indeed, the past decade has witnessed a renaissance of mast cell research ‘beyond allergy’, along with a more systematic exploration of the surprisingly wide range of physiological functions that mast cells may be involved in. The current debate sketches many of the exciting new horizons that have recently come into our vision during this intriguing, ongoing search.