Freshly isolated Thy-1+ dendritic epidermal cells express T cell receptor γδ-CD3

Abstract Within murine epidermis exists a population of Thy-1 + DEC which express membrane Thy-1 antigen, but lack CD8 or CD4 antigen. We examined freshly obtained non-cultured Thy-1 + DEC both by immunofluorescence and by biochemical techniques to identify the protein products of the T cell receptor (TCR) and the associated CD3 complex on these cells. Virtually all of the Thy-1 + DEC are brightly positive in CD3 expression with immunofluorescence using the monoclonal antibody 145-2C11. By immunoprecipitation, using this same antibody and polyclonal anti-TCR-γ antibody, the only TCR heterodimer detected on the freshly isolated Thy-1 + DEC is the γδ heterodimer. These findings suggest that in the phenotype and TCR expression, Thy-1 + DEC are analogous to CD8 − , CD4 − early fetal thymocytes.