Dermal γδ T cells - What have we learned?

Over the last several years, a number of papers have called attention to a distinct population of gamma delta T cells preferentially found in the dermis of the skin of normal mice. These cells appear to play an important role in promoting the development of psoriasis, but also are critical for host resistance to particular pathogens. They are characterized by the expression of a limited subset of gamma delta T cell receptors and a strong propensity to secrete IL-17. Perhaps most importantly, humans appear to carry an equivalent dermal gamma delta T cell population, likewise biased to secrete IL-17 and also implicated as playing a pathogenic role in psoriasis. This review will attempt to summarize and reconcile recent findings concerning the dermal gamma delta T cells. (C) 2015 Elsevier Inc. All rights reserved.