title: Expression of the Ly-5 alloantigenic system on epidermal cells.
abstract: The expression of Ly-5 alloantigens is confined to hemopoietic cell types and is therefore considered a valuable indicator for the bone marrow derivation of a given cell. The further finding that different hemopoietic cell lineages express different molecular forms of the Ly-5 alloantigens prompted us to investigate (1) whether murine epidermal cells or subpopulations thereof express Ly-5 specificities and if so, (2) whether the expression of particular molecular configurations of Ly-5 antigens would allow us to gain a clue about the derivation of certain epidermal cell populations. When epidermal sheets from BALB/c, C57Bl/6, and C3H/He mice, were exposed to monoclonal anti Ly-5.1 antibody in an indirect immunofluorescence technique, a system of evenly distributed, dendritic cells was visualized. Allelic exclusion of the Ly-5 system was demonstrated by replacing anti-Ly-5.1 antibody by anti-Ly-5.2 reagent and by using epidermal sheets from SJL/J mice. Studies on epidermal cell (EC) suspensions revealed that about 1.6-5.2% of C3H/He EC were Ly-5-reactive and that approximately equal numbers of Ly-5-positive cells bore either Thy-1 or Ia antigens. Electron microscopic studies disclosed two morphologically different Ly-5-positive cell populations, i.e., cells of the Langerhans cell lineage and a recently defined cell system, whose most prominent feature is the expression of the Thy-1 antigen. We have termed these cells dendritic Thy-1+EC (dTHY-1+EC). In order to define the molecular configurations of the Ly-5 alloantigens, EC and spleen cells were internally labeled and--after immunoprecipitation of cell-membrane detergent extracts with anti-Ly-5.1--were analyzed on sodium dodecyl sulfate-polyacrylamide gels. Spleen cells yielded 3 bands with a molecular weight of 180,000, 195,000, and 215,000, respectively, as is characteristic for T lymphocytes, non-T/non-B cells, and B lymphocytes. In contrast, a single 195,000-200,000 dalton band was found in precipitates of both untreated and Langerhans cell-depleted (anti-Ia+C) EC. These data demonstrate the existence and active biosynthesis of the Ly-5 alloantigenic system on certain EC populations, i.e., Langerhans cells and dThy-1+EC, and therefore imply that both cell types originate from a bone marrow-derived precursor. The expression of the same molecular configuration of Ly-5 alloantigens on both LC and dThy-1+EC suggest that these two cell populations do not belong either to the T-cell or to the B-cell lineage and imply an ontogenetic relationship between dThy-1+EC and Ia-positive EC.
authors.forename: H
authors.initials: H
authors.lastname: Leibl
authors.forename: J
authors.initials: J
authors.lastname: Hutterer
authors.forename: H
authors.initials: H
authors.lastname: Korschan
authors.forename: G
authors.initials: G
authors.lastname: Schuler
authors.forename: M
authors.initials: M
authors.lastname: Tani
authors.forename: E
authors.initials: E
authors.lastname: Tschachler
authors.forename: N
authors.initials: N
authors.lastname: Romani
authors.forename: K
authors.initials: K
authors.lastname: Wolff
authors.forename: G
authors.initials: G
authors.lastname: Stingl
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000950:Antigens, Ly / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis; D003712:Dendrites / Q000276:immunology; D000078404:Epidermal Cells; D005455:Fluorescent Antibody Technique; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007519:Isoantigens / Q000032:analysis*; D007801:Langerhans Cells / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D018800:Thy-1 Antigens
chemical_list: D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D000954:Antigens, Surface; D000949:Histocompatibility Antigens Class II; D007519:Isoantigens; D018800:Thy-1 Antigens