title: Professional presentation of antigen by activated human T cells.
abstract: Activated human T cells express class II molecules, but their capacity to present soluble antigens and stimulate T cells has been repeatedly questioned. Two lines of evidence indicate that T cells may indeed function as professional antigen-presenting cells. First, T cells that have been recently activated can efficiently capture, process and present tetanus toxoid to class II-restricted T cell clones. This capacity correlates with the rate of class II synthesis. Second, activated T cell clones express high levels of B7, are powerful stimulators in mixed lymphocyte reactions, and their stimulatory capacity is inhibited by soluble CTLA4 or anti-B7 antibody. Furthermore, expression of B7 can be detected in vivo on T cells from biopsies of patients with liver disease. Presentation of soluble antigen by activated T cells may play a role in the amplification of the specific response, and possibly in immunopathological states.
authors.affiliation: Fondazione A. Cesalpino, Basel, Switzerland.
authors.forename: V
authors.initials: V
authors.lastname: Barnaba
authors.forename: C
authors.initials: C
authors.lastname: Watts
authors.forename: M
authors.initials: M
authors.lastname: de Boer
authors.forename: P
authors.initials: P
authors.lastname: Lane
authors.forename: A
authors.initials: A
authors.lastname: Lanzavecchia
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology*; D018122:B7-1 Antigen / Q000096:biosynthesis; D002478:Cells, Cultured; D006681:HLA-D Antigens / Q000096:biosynthesis; D006801:Humans; D008099:Liver / Q000166:cytology; D008213:Lymphocyte Activation / Q000276:immunology*; D010873:Pinocytosis / Q000502:physiology; D011869:Radioligand Assay; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology*; D013745:Tetanus Toxoid / Q000276:immunology
chemical_list: D018122:B7-1 Antigen; D006681:HLA-D Antigens; D013745:Tetanus Toxoid