title: Peripheral T cells undergoing superantigen-induced apoptosis in vivo express B220 and upregulate Fas and Fas ligand.
abstract: Staphylococcal enterotoxin B (SEB) is a bacterial superantigen (SAg) that predominantly interacts with V(beta)8+ T cells. In vivo treatment of mice with SEB leads to an initial increase in the percentage of V(beta)8+ T cells, followed by a decrease in the numbers of these cells, eventually reaching lower levels than those found before treatment with the SAg. This decrease is due to apoptosis of the SEB-responding cells. In the present study, we use the distinct light scattering characteristics of apoptotic cells to characterize T cells that are being deleted in response to SEB in vivo. We show that dying, SEB-reactive T cells express high levels of Fas and Fas ligand (Fas-L), which are implicated in apoptotic cell death. In addition, the B cell marker B220 is upregulated on apoptotic cells. Moreover, we show that the generation of cells with an apoptotic phenotype is severely impaired in response to SEB in functional Fas-L-deficient mutant gld mice, confirming the role of the Fas pathway in SAg mediated peripheral deletion in vivo.
authors.affiliation: Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Renno
authors.forename: M
authors.initials: M
authors.lastname: Hahne
authors.forename: J
authors.initials: J
authors.lastname: Tschopp
authors.forename: H R
authors.initials: HR
authors.lastname: MacDonald
mesh_terms: D000818:Animals; D017209:Apoptosis; D001402:B-Lymphocytes / Q000276:immunology; D004768:Enterotoxins / Q000276:immunology*; D000939:Epitopes; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis; D012542:Scattering, Radiation; D018089:Superantigens / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D015854:Up-Regulation; D019014:fas Receptor / Q000096:biosynthesis
chemical_list: D004768:Enterotoxins; D000939:Epitopes; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018089:Superantigens; D019014:fas Receptor; C031818:enterotoxin B, staphylococcal; D017493:Leukocyte Common Antigens