Limited diversity of gamma delta antigen receptor genes of Thy-1+ dendritic epidermal cells.

T cells bearing gamma delta antigen receptors constitute minor populations in most peripheral lymphoid tissues but represent the major populations of T cells in certain epithelia, including the epidermis. We show that murine dendritic epidermal cell (dEC) clones express V gamma and V delta gene segments, which are rare in adult T cells but predominate in fetal thymocytes. Analysis of the junctions of the rearranged gamma and delta genes shows a striking homogeneity among the receptors of five dEC clones. Our data support a model in which dECs represent one of perhaps several waves of emigrants from the early fetal thymus, and imply a role for dECs in immune surveillance that is distinct from that of alpha beta- and other gamma delta-bearing T cells.