Murine CD4(+) CD25(+) regulatory T cells fail to undergo chromatin remodeling across the proximal promoter region of the IL-2 gene JOURNAL OF IMMUNOLOGY Su, L., Creusot, R. J., Gallo, E. M., Chan, S. M., Utz, P. J., Fathman, C. G., Ermann, J. 2004; 173 (8): 4994-5001

Abstract

CD4+CD25+ regulatory T cells (Treg) acquire unique immunosuppressive properties while maintaining an anergy phenotype when activated in vitro under conditions that induce IL-2 production and proliferation in conventional CD4+ T cells. We investigated the mechanism underlying one component of this naturally anergic phenotype, the inability of the Treg cells to produce IL-2 following activation. Analysis of freshly isolated murine CD4+CD25+ Treg and conventional CD4+CD25- T cells following PMA/ionomycin stimulation demonstrated no differences in inducible AP-1 formation, an important transcriptional complex in regulating IL-2 gene expression. Although p38 MAPK and ERK1/2 protein kinases were phosphorylated with similar kinetics, we observed diminished activation of JNK in the CD4+CD25+ Treg cells. However, lentiviral-mediated reconstitution of the JNK pathway using a constitutively active construct did not overcome the block in IL-2 synthesis. Using a PCR-based chromatin accessibility assay we found that the minimal IL-2 promoter region of CD4+CD25+ Treg cells, unlike conventional CD4 T cells, did not undergo chromatin remodeling following stimulation, suggesting that the inability of CD4+CD25+ Treg cells to secrete IL-2 following activation is controlled at the chromatin level.

View details for Web of Science ID 000224392200028

View details for PubMedID 15470042