Identification and characterization of novel dermal Thy-1 antigen-bearing dendritic cells in murine skin.

Using immunofluorescence on dermal sheets of mouse ear, we identified novel Thy-1+ dermal dendritic cells in murine skin. These cells are resistant to topical corticosteroid treatment. The number of these dermal Thy-1+ dendritic cells is not altered with aging of the mice or with 3 d of culture. Dermal Thy-1+ dendritic cells have melanosomes in their cytoplasm; hence, phagocytic activity is likely to be present. Double immunofluorescence revealed that most of these dermal Thy-1+ dendritic cells express CD45. Furthermore, conventional immunofluorescence and confocal laser scanning microscopic findings showed that most of these Thy-1+ dermal dendritic cells express gamma delta and V gamma 3 T-cell receptors. The relationship between these dermal Thy-1+ dendritic cells and dendritic epidermal T cells is discussed.