title: Dissection of the function of HLA class II and costimulation in B cell-mediated and toxic shock syndrome toxin-1-induced T cell proliferation.
abstract: In this study we have demonstrated that costimulation for TSST-1-induced T cell proliferation is provided by HLA class II negative accessory B cells. In addition, TSST-1 binding to these HLA class II negative accessory B cells could not be detected by immunocytofluorescence, or in a system in which T cell proliferation depended on TSST-1 pretreated HLA class II negative B cells. These findings suggest that accessory signals can be supplied by B cells that are not involved in the activation of T cells via Ag-HLA/TCR-CD3 complex interaction: TCR ligation by a TSST-1/HLA complex and costimulation need not be delivered by the same cell. In the presence of HLA class II negative B cells, T cell proliferation in response to TSST-1 could be achieved despite addition of a mAb that can block HLA class II binding sites for TSST-1. These findings suggest the possibility that TSST-1 may directly ligate TCR. In the presence of anti-BB1-treated HLA class II negative accessory cells, TSST-1-induced T cell proliferation was inhibited by over 50% indicating the involvement of the BB1/CD28 pathway. The leukemic pre-B cell lines NALM-6, and BLIN-1, both of which express surface HLA class II Ag, but not the costimulatory B cell activation Ag BB1, were deficient in their accessory function for T cell proliferation in response to the superantigen TSST-1 and the mitogen Con A.
authors.affiliation: Sloan-Kettering Institute, Department of Pediatrics, New York, NY.
authors.forename: D
authors.initials: D
authors.lastname: Dennig
authors.forename: R J
authors.initials: RJ
authors.lastname: O'Reilly
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D018122:B7-1 Antigen; D001427:Bacterial Toxins; D004768:Enterotoxins / Q000276:immunology* / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000502:physiology; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D013211:Staphylococcus aureus / Q000472:pathogenicity*; D018089:Superantigens; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D018122:B7-1 Antigen; D001427:Bacterial Toxins; D004768:Enterotoxins; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal