Molecular aspects of epithelial γδ T cell regulation

gamma delta T cells lie at the interface between innate and adaptive immunity, sharing features with both arms of the immune system. The vast majority of gamma delta T cells reside in epithelial layers of tissues such as skin, gut, lung, tongue and reproductive tract where they provide a first line of defense against environmental attack. The existence of epithelium-resident gamma delta T cells has been known for over 20 years but our understanding of the molecular events regulating development and function of these cells is incomplete. We review recent advances in the field, with particular emphasis on the gamma delta T cell population resident in mouse epidermis. These studies have enhanced our knowledge and understanding of the life cycle of this enigmatic population of cells.