title: Antigen presenting ability of thymic macrophages and epithelial cells: evidence for defects in the antigen processing function of thymic epithelial cells.
abstract: We compared the antigen presenting ability of cloned thymic macrophage and epithelial cell lines using T cell hybridomas with well-characterized activation requirements. A cloned thymic epithelial cell line (3D.1), preinduced with interferon-gamma (IFN-gamma) activated the T cell hybridoma 3DO-18.3 but not the T cell hybridoma DO-11.10. Analyses using preprocessed antigen suggest that the failure of 3D.1 to activate DO-11.10 is due to its inability to process chicken ovalbumin to produce a peptide recognized by the Ag:MHC T cell receptor of DO-11.10. The epithelial cell line 3D.1 was able to activate DO-11.10 if the superantigen staphylococcal enterotoxin B was used for activation instead of ovalbumin. These observations indicate that IFN-gamma-induced 3D.1 expresses sufficient I-Ad molecules to activate DO-11.10 but is unable to produce the peptide of ovalbumin recognized by DO-11.10. Furthermore, 3D.1 appears to be representative of nonmacrophage thymic stromal cells cultured in vitro, since heterogeneous cultures containing epithelial cells exhibited the same selective T cell activation characteristics. In contrast, thymic macrophage cell lines activated all T cells studied. These results suggest that there is a functional difference between the capacity of thymic epithelial cells and macrophages to process and present antigen to T cells.
authors.affiliation: Department of Immunology, DNAX Research Institute, Palo Alto, California 94304.
authors.forename: J
authors.initials: J
authors.lastname: Ransom
authors.forename: R
authors.initials: R
authors.lastname: Wu
authors.forename: M
authors.initials: M
authors.lastname: Fischer
authors.forename: A
authors.initials: A
authors.lastname: Zlotnik
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D002478:Cells, Cultured; D004848:Epithelium / Q000276:immunology; D006825:Hybridomas; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D010446:Peptide Fragments / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*
chemical_list: D010446:Peptide Fragments; D007371:Interferon-gamma; D010047:Ovalbumin