Distinct roles for LFA-1 and CD28 during activation of naive T cells: adhesion versus costimulation

Détails

ID Serval
serval:BIB_515AFB41850C
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Distinct roles for LFA-1 and CD28 during activation of naive T cells: adhesion versus costimulation
Périodique
Immunity
Auteur(s)
Bachmann  M. F., McKall-Faienza  K., Schmits  R., Bouchard  D., Beach  J., Speiser  D. E., Mak  T. W., Ohashi  P. S.
ISSN
1074-7613 (Print)
Statut éditorial
Publié
Date de publication
10/1997
Volume
7
Numéro
4
Pages
549-57
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Oct
Résumé
Efficient T cell activation requires the engagement of a variety of ligand/receptor molecules in addition to T cell receptor (TCR)-major histocompatibility complex (MHC)/peptide interactions. The leukocyte function antigen 1 (LFA-1) and the CD28 glycoprotein have both been implicated in T cell activation. The present study dissects the roles of LFA-1 and CD28 in the activation of naive virus-specific CD8+ T cells. We demonstrate that LFA-1 facilitates T cell activation by lowering the amounts of antigen necessary for T cell activation. In the absence of LFA-1, 100-fold more antigen was required for T cell-antigen-presenting cell (APC) conjugation and all subsequent events of T cell activation, including TCR down-regulation, Ca2+-flux, T cell proliferation, and lytic effector cell induction. Thus, LFA-1 facilitates the functional triggering of TCRs by promoting adhesion of T cells to APCs but does not affect T cell activation otherwise. In contrast, CD28 played an entirely different role during T cell activation. CD28 reduced the number of TCRs that had to be triggered for T cell activation and allowed activation of T cells by low affinity ligands. CD28 but not LFA-1 prevented induction of T cell unresponsiveness after stimulation of TCRs. These results demonstrate that LFA-1 and CD28 exhibit distinct, nonoverlapping ways to influence T cell activation and suggest that the terms costimulation and signal 2 should be revisited.
Mots-clé
Animals Antigen-Presenting Cells/immunology Antigens, CD28/*physiology Antigens, Viral/immunology Calcium/physiology Cell Adhesion Cell Adhesion Molecules/physiology Clonal Anergy Down-Regulation Interleukin-2/physiology *Lymphocyte Activation Lymphocyte Function-Associated Antigen-1/*physiology Lymphocytic choriomeningitis virus/immunology Mice Mice, Transgenic Peptides/immunology Receptors, Antigen, T-Cell/metabolism Signal Transduction T-Lymphocytes/*immunology
Pubmed
Web of science
Open Access
Oui
Création de la notice
28/01/2008 12:33
Dernière modification de la notice
08/05/2019 18:34
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