cAMP response element modulator α controls IL2 and IL17A expression during CD4 lineage commitment and subset distribution in lupus

This is the authors' abstract. We don't add key points for this paper.

Appropriate expression of IL-2 plays a central role during the priming and differentiation of T cells. A tight balance between IL-2 and the effector cytokine IL-17A is essential for immune homeostasis. Epigenetic mechanisms have been documented as a key component of cytokine regulation during lineage commitment. The molecular mechanisms that induce chromatin remodeling are less well understood. We investigated epigenetic regulators that mediate the diametric expression of IL-2 and IL-17A in naive, central memory, and effector memory CD4(+) T cells. We demonstrate that cAMP response modulator (CREM)α contributes to epigenetic remodeling of IL2 in effector memory T cells through the recruitment of DNMT3a. CREMα also reduces CpG-DNA methylation of the IL17A promoter. CREMα expression is regulated at the epigenetic level by CpG-DNA methylation, which allows increased CREMα expression in effector memory CD4(+) T cells. T cells from patients with systemic lupus erythematosus (SLE) express increased levels of CREMα and exhibit a phenotype that is similar to effector memory CD4(+) T cells with epigenetically predetermined expression patterns of IL-2 and IL-17A. We conclude that CREMα mediates epigenetic remodeling of the IL2 and IL17A gene during T-cell differentiation in favor of effector memory T cells in health and disease.