CREB regulates Foxp3⁺ST-2⁺ T_REGS with enhanced IL-10 production

Area of Science:

• Immunology
• Molecular Biology
• Cellular Biology

Background:

• Regulatory T-cells (Tregs) are crucial for immune homeostasis, characterized by Foxp3 expression.
• Foxp3 expression is regulated by the Treg-specific demethylated site (TSDR), which contains a CREB binding site.

Purpose of the Study:

• To investigate the impact of CREB deletion on Treg development, stability, and function.
• To elucidate the molecular mechanisms underlying CREB's role in Treg biology.

Main Methods:

• Flow cytometry for Treg frequency and phenotype analysis (CD25+/Foxp3+).
• Cytokine analysis via ELISA and RT-qPCR.
• Gene expression profiling (Affymetrix HTA2), ATAC-sequencing, and methylation assays.
• In vivo functional assessment using a CD4 T cell-mediated transfer colitis model.

Main Results:

• Foxp3-specific CREB deletion increased Treg frequencies in various organs but decreased Foxp3 expression per cell.
• CREB-deficient Tregs showed enhanced expression of IL-33 receptor (ST-2), IL-10, IL-13, and CREM.
• These Tregs exhibited potent suppressive capacity in vitro and ameliorated colitis in vivo via IL-10.

Conclusions:

• CREB plays a dual role in Tregs: promoting Foxp3 expression and, with CREM, restricting chromatin accessibility at the ST2 locus.
• This regulation balances Treg stability and IL-10-mediated immune suppression.
• Targeting CREB in Tregs may offer therapeutic strategies for inflammatory diseases.