title: Origin of Thy-1+ dendritic epidermal cells of adult mice from fetal thymic precursors.
abstract: The skin of mice contains dendritic epidermal cells carrying the Thy-1 antigen (Thy-1+ dEC) which express antigen receptors composed of the T-cell antigen receptor (TCR) gamma- and delta-chains. Although the role of the thymus in the generation of most T cells is well established, the involvement of the thymus in the generation of Thy-1+ dEC is not clear. Because bone marrow cells can give rise in Thy-1+ dEC in chimaeric mice and Thy-1+ dEC are detected in the skin of athymic nude nice, it has been proposed that Thy-1+ dEC arise continuously from bone marrow precursors by a thymus-independent mechanism. But it has recently been determined that Thy-1+ dEC in nude mice do not express TCR at the cell surface, and that the gamma- and delta-chain genes are in germ-line configuration, leaving the role of the thymus in the generation of Thy-1+ dEC uncertain. Most Thy-1+ dEC in all normal mouse strains examined express TCR containing the V gamma 3 gene product. This V gene segment is expressed on the first wave of TCR-expressing cells to emerge during fetal development, and in adult mice is detectable only on cells in the epidermis. In addition to use of this 'fetal' V gamma segment, other features of the Thy-1+ dEC TCR genes, including absence or minimal presence of nongerm-line-encoded nucleotides at the junctions and use of a single D element in the rearranged delta-chain gene are typical of rearrangements found in fetal, and not adult, thymus. Here we demonstrate that precursors that are present only in the fetal thymus give rise to Thy-1+ dEC in the skin of adult mice.
authors.affiliation: Cancer Research Laboratory, University of California, Berkeley 94720.
authors.forename: W L
authors.initials: WL
authors.lastname: Havran
authors.forename: J P
authors.initials: JP
authors.lastname: Allison
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000954:Antigens, Surface / Q000032:analysis*; D003713:Dendritic Cells / Q000166:cytology* / Q000276:immunology; D000078404:Epidermal Cells; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D016692:Receptors, Antigen, T-Cell, gamma-delta; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology* / Q000637:transplantation
chemical_list: D000954:Antigens, Surface; D011948:Receptors, Antigen, T-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta; D018800:Thy-1 Antigens