Identification of a T3-associated γδ T cell receptor on thy-1⁺ dendritic epidermal cell lines

The murine epidermis contains a subpopulation of bone marrow-derived lymphocytes that have a dendritic morphology and that express Thy-1 and T3 cell-surface antigens but not other markers (L3T4 or Lyt-2) characteristic of mature peripheral T lymphocytes. An alternative type of T cell receptor was earlier identified on a subpopulation of murine thymocytes with a similar phenotype (T3⁺, L3T4^-, Lyt-2^-), but not on peripheral murine T lymphocytes. Two independently derived Thy-1⁺, L3T4^-, and Lyt-2^- dendritic cell lines of epidermal origin that express a T3-associated disulfide-linked heterodimer composed of a 34-kilodalton γ-chain and 46-kilodalton partner (the δ chain) have now been identified. Analysis of N-linked gtycosylation revealed that this receptor is similar to that detected on thymocytes. These results demonstrate that Thy-1⁺ dendritic epidermal cell lines can express γδ T cell receptors in vitro and suggest that Thy-1⁺ dendritic epidermal cells express such receptors in vivo. The localization of these γδ T cell receptor-expressing cells in the epidermis may be of importance for understanding the function of these receptors.