The Role of Tissue-resident γδ T Cells in Stress Surveillance and Tissue Maintenance

While forming a minor population in the blood and lymphoid compartments, gamma delta T cells are significantly enriched within barrier tissues. In addition to providing protection against infection, these tissue-resident gamma delta T cells play critical roles in tissue homeostasis and repair. gamma delta T cells in the epidermis and intestinal epithelium produce growth factors and cytokines that are important for the normal turnover and maintenance of surrounding epithelial cells and are additionally required for the efficient recognition of, and response to, tissue damage. A role for tissue-resident gamma delta T cells is emerging outside of the traditional barrier tissues as well, with recent research indicating that adipose tissue-resident gamma delta T cells are required for the normal maintenance and function of the adipose tissue compartment. Here we review the functions of tissue-resident gamma delta T cells in the epidermis, intestinal epithelium, and adipose tissue, and compare the mechanisms of their activation between these sites.