title: The effect of staphylococcal enterotoxin B on thyrocyte HLA molecule expression.
abstract: Microbial superantigens have been implicated in the pathogenesis of human autoimmune diseases. In autoimmune glands, thyrocytes inappropriately express HLA-DR molecules and these cells may function as antigen presenting cells (APC) We studied the effect in vitro of staphylococcal enterotoxin B (SEB) on HLA molecule expression on thyrocytes obtained from autoimmune and non-autoimmune glands by immunofluorescence. HLA class I and class II upregulation could be detected by FACS analysis on thyrocytes. Anti-IFN-gamma neutralizing antibodies markedly affect both class I and class II upregulation on thyrocytes. FRTL5 cells were not responsive to SEB. Similarly, a human thyroid cell strain maintained in culture in a conditioned medium was not induced to express HLA products by SEB stimulation. The addition of autologous intrathyroidal lymphocytes caused reestablishment of the SEB effect.
mesh_terms: D002478:Cells, Cultured; D004768:Enterotoxins / Q000494:pharmacology*; D005434:Flow Cytometry; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000276:immunology*; D018089:Superantigens / Q000494:pharmacology*; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D015854:Up-Regulation