title: Induction and functional characterization of class II MHC (Ia) antigens on murine keratinocytes.
abstract: To induce Ia molecules on the surface of murine keratinocytes (KC), healthy mice were treated daily with i.p. injections of rIFN-gamma at a dose of 50,000 U/day for 6 days. This resulted in strong Ia expression by KC as determined by immunofluorescence of epidermal sheets or cell suspensions with anti-class II mAb. To obtain a population of Ia-bearing KC devoid of Langerhans cells, a method of depleting Langerhans cells from such suspensions was developed. Although Ia+ KC were unable to stimulate allogeneic T cells in a primary epidermal cell-lymphocyte reaction (less than 5% control), they did induce a proliferative response in an allospecific T cell line. Ia+ KC were unable to present native peptide molecules to class II restricted, Ag-specific T cell hybridomas. However, Ia+ KC were able to present a peptide fragment of pigeon cytochrome c to a hybridoma, suggesting that although these cells cannot process native protein Ag, they can present antigenic peptides. Ia+ (but not Ia-) KC also served as targets for class II restricted cytolytic T cell clones. These data indicate that the Ia expressed by KC is a functional molecule, and that Ia+ KC can participate in some immunologic reactions.
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D000078404:Epidermal Cells; D004817:Epidermis / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000145:classification / Q000276:immunology*; D007371:Interferon-gamma / Q000494:pharmacology; D007801:Langerhans Cells / Q000276:immunology; D051379:Mice; D010446:Peptide Fragments / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000949:Histocompatibility Antigens Class II; D010446:Peptide Fragments; D007371:Interferon-gamma