title: Thy-1+ dendritic cells in murine epidermis are bone marrow-derived.
abstract: Thy-1+, Ly-5+ dendritic cells have recently been described as a resident cell population in murine epidermis, but their ontogeny and function are unknown. We therefore investigated the origin and turnover of epidermal Thy-1+ cells utilizing chimeric mice. Lethally x-irradiated AKR/J (Thy-1.1+) and AKR/Cum (Thy-1.2+) mice were reconstituted with allogeneic bone marrow cells with or without thymocytes from congenic AKR/Cum or AKR/J mice, respectively. The density of residual indigenous Thy-1.1+ cells in AKR/J chimeras and Thy-1.2+ cells in AKR/Cum chimeras was substantially reduced following x-irradiation, as determined by immunofluorescence staining of epidermal sheets. Epidermal repopulation by allogeneic Thy-1+ dendritic epidermal cells was first observed at 5 weeks in AKR/J chimeras and at 7 weeks in AKR/Cum chimeras and progressed slowly. Repopulation was not enhanced by increasing the number of allogeneic bone marrow cells injected from 2 X 10(7) to 10(8) cells or by the addition of 8 X 10(7) allogeneic thymocytes to the donor inoculate. Epidermal repopulation by allogeneic Thy-1.2+ cells was not seen in AKR/J mice reconstituted with syngeneic bone marrow cells and allogeneic Thy-1.2+ AKR/Cum thymocytes. Taken together, these results indicate that Thy-1+ dendritic epidermal cells are derived from the bone marrow and suggest that they are not related to conventional peripheral T-lymphocytes.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis; D001853:Bone Marrow / Q000276:immunology / Q000528:radiation effects; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D002678:Chimera; D000078404:Epidermal Cells; D004817:Epidermis / Q000276:immunology; D005260:Female; D005455:Fluorescent Antibody Technique; D051379:Mice; D008806:Mice, Inbred AKR / Q000276:immunology*; D010641:Phenotype; D013154:Spleen / Q000166:cytology / Q000528:radiation effects; D013950:Thymus Gland / Q000166:cytology / Q000528:radiation effects; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal