Molecular mechanisms underlying differential contribution of CD28 versus non-CD28 costimulatory molecules to IL-2 promoter activation.
J Immunol
; 168(8): 3847-54, 2002 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-11937538
ABSTRACT
T cell costimulation via CD28 and other (non-CD28) costimulatory molecules induces comparable levels of [(3)H]TdR incorporation, but fundamentally differs in the contribution to IL-2 production. In this study, we investigated the molecular basis underlying the difference between CD28 and non-CD28 costimulation for IL-2 gene expression. Resting T cells from a mutant mouse strain generated by replacing the IL-2 gene with a cDNA encoding green fluorescent protein were stimulated with a low dose of anti-CD3 plus anti-CD28 or anti-non-CD28 (CD5 or CD9) mAbs. CD28 and non-CD28 costimulation capable of inducing potent [(3)H]TdR uptake resulted in high and marginal levels of green fluorescent protein expression, respectively, indicating their differential IL-2 promoter activation. CD28 costimulation exhibited a time-dependent increase in the binding of transcription factors to the NF-AT and NF-kappaB binding sites and the CD28-responsive element of the IL-2 promoter, whereas non-CD28 costimulation did not. Particularly, a striking difference was observed for the binding of NF-kappaB to CD28-responsive element and the NF-kappaB binding site. Decreased NF-kappaB activation in non-CD28 costimulation resulted from the failure to translocate a critical NF-kappaB member, c-Rel, to the nuclear compartment due to the lack of IkappaBbeta inactivation. These observations suggest that unlike CD28 costimulation, non-CD28 costimulation fails to sustain IL-2 promoter activation and that such a failure is ascribed largely to the defect in the activation of c-Rel/NF-kappaB.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Nucleares
/
Regulação da Expressão Gênica
/
Interleucina-2
/
Regiões Promotoras Genéticas
/
Antígenos CD28
/
Proteínas I-kappa B
Limite:
Animals
Idioma:
En
Revista:
J Immunol
Ano de publicação:
2002
Tipo de documento:
Article