cAMP response element modulator α controls IL2 and IL17A expression during CD4 lineage commitment and subset...

Area of Science:

• Immunology
• Epigenetics
• T cell biology

Background:

• Interleukin-2 (IL-2) and IL-17A cytokine balance is crucial for immune homeostasis.
• Epigenetic mechanisms regulate cytokine expression during T cell lineage commitment.
• Molecular pathways driving chromatin remodeling in T cells remain incompletely understood.

Purpose of the Study:

• Investigate epigenetic regulators controlling the opposing expression of IL-2 and IL-17A in distinct CD4+ T cell subsets.
• Elucidate the role of cAMP response modulator alpha (CREMα) in mediating these epigenetic changes.
• Examine the relevance of these findings in the context of systemic lupus erythematosus (SLE).

Main Methods:

• Analysis of epigenetic regulators in naive, central memory, and effector memory CD4+ T cells.
• Assessing the recruitment of DNMT3a by CREMα.
• Measuring CpG-DNA methylation at the IL17A promoter.
• Investigating CREMα expression regulation by DNA methylation.
• Comparing T cells from healthy individuals and SLE patients.

Main Results:

• CREMα mediates IL2 epigenetic remodeling in effector memory T cells via DNMT3a recruitment.
• CREMα reduces CpG-DNA methylation of the IL17A promoter.
• CpG-DNA methylation epigenetically regulates CREMα expression, increasing it in effector memory T cells.
• T cells in SLE patients show elevated CREMα and a phenotype mirroring effector memory cells with altered IL-2/IL-17A epigenetic programming.

Conclusions:

• CREMα drives epigenetic remodeling of IL2 and IL17A genes during T cell differentiation.
• This remodeling favors an effector memory T cell phenotype in both healthy and disease states.
• CREMα represents a key epigenetic mediator in T cell plasticity and immune dysregulation in SLE.