The role of CD4-Lck in T-cell receptor antagonism: evidence for negative signaling.
Proc Natl Acad Sci U S A
; 93(19): 10360-5, 1996 Sep 17.
Article
em En
| MEDLINE
| ID: mdl-8816805
ABSTRACT
Small changes in the complex between a peptide and a molecule of the major histocompatibility complex generate ligands able to partially activate (partial agonist) or even inhibit (antagonist) T-cell functions. T-cell receptor engagement of antagonist complex results in a partial zeta chain phosphorylation without activation of the associated ZAP-70 kinase. Herein we show that, despite a strong inhibition of both inositol phospholipid hydrolysis and extracellular increasing antagonist concentrations increased the activity of the CD4-Lck kinase. Addition of anti-CD4 antibody to culture medium prevented inhibitory effects induced by antagonist ligand. We propose that CD4-Lck activation triggered by antagonist complexes may act in a dominant negative mode, thus overriding stimulatory signals coming from agonist ligand. These findings identify a new T-cell signaling profile that may explain the ability of some T-cell receptor variant ligands to inhibit specific biological activities or trigger alternative activation programs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Antígenos de Linfócitos T
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Linfócitos T
/
Antígenos CD4
/
Quinases da Família src
/
Células Apresentadoras de Antígenos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Itália