title: CD154-CD40-independent up-regulation of B7-2 on splenic antigen-presenting cells and efficient T cell priming by staphylococcal enterotoxin A.
abstract: It has been demonstrated that in vivo T cell priming requires CD154-CD40 interaction, which is suggested to be critical in the induction of co-stimulatory activities on antigen-presenting cells (APC). In the current study, we demonstrate that in vivo administration of a high dose of a superantigen, staphylococcal enterotoxin A (SEA), could up-regulate B7-2 on most splenic APC independently of the CD154-CD40 interaction, followed by efficient expansion of SEA-reactive V(beta)3(+) T cells in CD154- or CD40-deficient mice. However, the CD154-CD40 interaction may be involved in SEA-mediated T cell activation, since a contribution of the CD154-CD40 interaction was observed when a lower dose of SEA was injected. CD154-independent T cell priming by SEA appeared also independent of the TRANCE-RANK pathway, which was shown to be capable of mediating CD154-independent activation of naive T cells during the infection of some viruses. These results indicate that SEA, which provokes rapid and efficient T cell responses without adjuvant, could utilize multiple CD154/TRANCE-independent pathways, to prime T cells.
authors.affiliation: Section of Immunobiology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520, USA.
authors.forename: Koji
authors.initials: K
authors.lastname: Eshima
authors.forename: Yongwon
authors.initials: Y
authors.lastname: Choi
authors.forename: Richard A
authors.initials: RA
authors.lastname: Flavell
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D015703:Antigens, CD / Q000096:biosynthesis*; D051940:B7-2 Antigen; D019013:CD40 Antigens / Q000235:genetics / Q000502:physiology; D023201:CD40 Ligand / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004768:Enterotoxins / Q000494:pharmacology*; D007141:Immunoglobulin Fc Fragments / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D051379:Mice; D018345:Mice, Knockout; D013154:Spleen / Q000166:cytology / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D051940:B7-2 Antigen; D019013:CD40 Antigens; C497965:Cd86 protein, mouse; D004768:Enterotoxins; D007141:Immunoglobulin Fc Fragments; D008562:Membrane Glycoproteins; D023201:CD40 Ligand; C026066:enterotoxin A, Staphylococcal; D007371:Interferon-gamma