Since starting her own laboratory at The Scripps Research Institute in 1991, immunologist Wendy Havran has been searching for the answer to a single question: What activates gamma-delta T cells? These immune cells make up a small proportion of the T cells in blood and lymphoid organs but are abundant in body barrier tissues, residing permanently in the skin of mice and humans. They act as rapid responders, recognizing tissue damage and secreting growth factors and other signaling molecules that alert immune cells that aren’t in the skin to migrate and assist in healing.
“During resting conditions when there is no damage, the skin gamma-delta T cells . . . have these dendrites that they extend and retract, touching their epithelial cell neighbors to survey for any damage or disease,” Havran explains. When there is damage, the T cells gather, migrate to the damaged site, and begin to repair the ...
