Subset‐specific, uniform activation among Vγ6/Vδ1 + γδ T cells elicited by inflammation

The Vγ6/Vδ1 + cells, the second murine γδ T cell subset to arise in the thymus, express a nearly invariant T cell receptor (TCR), colonize select tissues, and expand preferentially in other tissues during inflammation. These cells are thought to help in regulating the inflammatory response. Until now, Vγ6/Vδ1 + cells have only been detectable indirectly, by expression of Vγ6‐encoding mRNA. Here, we report that 17D1, a monoclonal antibody, which detects the related epidermis‐associated Vγ5/Vδ1 + TCR, will also bind the Vγ6/Vδ1 + cells if their TCR is first complexed to an anti‐Cδ antibody. Features of this special condition for recognition suggest the possibility that an alternate structure exists for the Vγ6/Vδ1 TCR, which is stabilized upon binding to the anti‐Cδ antibody. Using the 17D1 antibody as means to track this γδ T cell subset by flow cytometry, we discovered that the response of Vγ6/Vδ1 + cells during inflammation often far exceeds that of other subsets and that the responding Vγ6/Vδ1 + cells display a strikingly uniform activation/memory phenotype compared with other γδ T cell subsets.