V beta specificity of superantigen TSST-1 plus CD28 costimulation without APCs.
Little has so far been known about the role of antigen-presenting cells (APCs) in the activation of T cells by superantigens. Recently several studies showed that superantigens could directly activate purified T cells in the presence of CD28 costimulation. Here we investigate V beta expression of T cells activated by the superantigen toxic shock syndrome toxin-1 (TSST-1), plus CD28 costimulation, in the absence of APCs. The aim of this study was to ask if TSST-1 activated purified T cells in the presence of CD28 costimulation with the same specificity as in the presence of APCs. We provide evidence that the specificity of TSST-1 to human V beta, in the presence of CD28 costimulation, is identical to that in the presence of APCs, with V beta 2 being significantly expanded. The results indicate that the main role of APCs in the superantigen-mediated T cell activation may be to provide T cells with CD28 costimulation.
Department of Immunology, Third Military Medical University, Chongqing, Sichuan, People's Republic of China.
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D000328:Adult; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001427:Bacterial Toxins; D018106:CD28 Antigens / Q000502:physiology*; D004768:Enterotoxins / Q000276:immunology*; D000939:Epitopes / Q000032:analysis / Q000502:physiology*; D006801:Humans; D008213:Lymphocyte Activation; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D013211:Staphylococcus aureus / Q000276:immunology; D018089:Superantigens / Q000032:analysis / Q000502:physiology*
D001427:Bacterial Toxins; D018106:CD28 Antigens; D004768:Enterotoxins; D000939:Epitopes; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal