Details

Autor(en) / Beteiligte

• Valanciuté, Asta
• le Gouvello, Sabine
• Solhonne, Brigitte
• Pawlak, André
• Grimbert, Philippe
• Lyonnet, Luc
• Hue, Sophie
• Lang, Philippe
• Remy, Philippe
• Salomon, Rémy
• Bensman, Albert
• Guellaën, Georges
• Sahali, Djillali

Titel

NF-kappa B p65 antagonizes IL-4 induction by c-maf in minimal change nephrotic syndrome

Ist Teil von

• The Journal of immunology (1950), 2004-01, Vol.172 (1), p.688-698

Ort / Verlag

United States

Erscheinungsjahr

2004

Link zum Volltext

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• Mechanisms underlying the pathophysiology of minimal change nephrotic syndrome (MCNS), the most frequent of glomerular diseases in children, remain elusive, although recent arguments suggest that T cell dysfunction may be involved in the pathogenesis of this disease. Recently, we reported that activated T cells of these patients display a down-regulation of IL-12R beta2 chain, suggesting an early commitment toward Th2 phenotype. In this study, we show that the short form of the proto-oncogene c-maf, a known activator of the IL-4 gene, is highly induced in MCNS T cells during relapse, where it translocates to the nuclear compartment and binds to the DNA responsive element. Unexpectedly, the nuclear localization of c-maf did not promote the IL-4 gene transcription in relapse. Using several approaches, we show in this study that RelA blunts IL-4 induction in T cells during the relapse in these patients. We demonstrate that the ex vivo inhibition of proteasome activity in T cells from relapse, which blocks NF-kappaB activity, strongly increases the IL-4 mRNA levels. Overexpression of c-maf in T cells induces a high level of IL-4 promoter-driven luciferase activity. In contrast, coexpression of c-maf with NF-kappaB RelA/p50, or RelA, but not p50, inhibits the c-maf-dependent IL-4 promoter activity. Finally, we demonstrated that, in T cell overexpressing RelA and c-maf, RelA expelled c-maf from its DNA binding site on IL-4 gene promoter, which results in active inhibition of IL-4 gene transcription. Altogether, these results suggest that the involvement of c-maf in Th2 commitment in MCNS operates through IL-4-independent mechanisms.