CD4-mediated signals induce T cell dysfunction in vivo.
J Immunol
; 163(2): 644-9, 1999 Jul 15.
Article
en En
| MEDLINE
| ID: mdl-10395653
Triggering of CD4 coreceptors on both human and murine T cells can suppress TCR/CD3-induced secretion of IL-2. We show here that pretreatment of murine CD4+ T cells with the CD4-specific mAb YTS177 inhibits the CD3-mediated activation of the IL-2 promoter factors NF-AT and AP-1. Ligation of CD4 molecules on T cells leads to a transient stimulation of extracellular signal-regulated kinase (Erk) 2, but not c-Jun N-terminal kinase (JNK) activity. Pretreatment with anti-CD4 mAb impaired anti-CD3-induced Erk2 activation. Costimulation with anti-CD28 overcame the inhibitory effect of anti-CD4 Abs, by induction of JNK activation. The in vivo relevance of these studies was demonstrated by the observation that CD4+ T cells from BALB/c mice injected with nondepleting anti-CD4 mAb were inhibited in their ability to respond to OVA Ag-induced proliferation and IL-2 secretion. Interestingly, in vivo stimulation with anti-CD28 mAb restored IL-2 secretion. Furthermore, animals pretreated with anti-CD4 elicited enhanced IL-4 secretion induced by OVA and CD28. These observations suggest that CD4-specific Abs can inhibit T cell activation by interfering with signal 1 transduced through the TCR, but potentiate those delivered through the costimulatory molecule CD28. These studies have relevance to understanding the mechanism of tolerance induced by nondepleting anti-CD4 mAb used in animal models for allograft studies, autoimmune pathologies, and for immunosuppressive therapies in humans.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Linfocitos T
/
Transducción de Señal
/
Antígenos CD4
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Immunol
Año:
1999
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos