Dendritic epidermal T-cell activation

Although gamma delta T cells compose a small proportion of lymphocytes in lymphoid compartments and peripheral blood, they are the major T-cell population present in epithelial tissues. However, the role played by gamma delta TCR expressing intraepithelial lymphocytes (IEL) has been enigmatic. The location of tissue-resident IEL suggests that they are important members of the first line of defense against insult for organs exposed to the environment, including the skin, gut, lungs, and reproductive system. Dendritic epidermal T cells (DETC) are the skin-resident gamma delta IEL and serve as a model system for gamma delta IEL in other locations. DETC have demonstrated importance in the modulation of immune responses, surveillance and repair of tissue, and resistance to infection. This work discusses recent developments in understanding DETC activation.