title: Forced contact between antigen-presenting cells and T cells: consequences for T-cell activation.
abstract: It is still not known how T cells are activated, which T-cell surface structures transmit activation signals, and if antigen-presenting cells possess activation structures for T cells. We have studied whether the T-cell receptor (TcR) must be engaged for T-cell activation to occur. By using membrane-incorporated monoclonal antibodies, we artificially forced T cells to bind to antigen-presenting cells in a mixed lymphocyte reaction system and thereby bypassed the need for TcR engagement and also made it possible for any surface molecule on antigen-presenting cells to deliver a stimulatory signal to the T cells. Theoretically, T cells would become polyclonally activated by this procedure. However, we found that they did not, even though they were intimately bound to the antigen-presenting cell, thus demonstrating that the TcR must participate in antigen/MHC binding in order for the T cells to become activated. This study does not exclude the possibility that antigen-presenting cells possess structures that can activate T cells.
authors.affiliation: Department of Immunology, Arrhenius Laboratories for Natural Science, University of Stockholm, Sweden.
authors.forename: I
authors.initials: I
authors.lastname: Höidén
authors.forename: B
authors.initials: B
authors.lastname: Clinchy
authors.forename: G
authors.initials: G
authors.lastname: Möller
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology* / Q000502:physiology; D017252:CD3 Complex; D002846:Chromatography, Affinity; D005455:Fluorescent Antibody Technique; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis; D008055:Lipids; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D011948:Receptors, Antigen, T-Cell / Q000276:immunology* / Q000502:physiology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D015395:Histocompatibility Antigens Class I; D007376:Interleukin-2; D008055:Lipids; D011948:Receptors, Antigen, T-Cell