Prolyl hydroxylase 3 (PHD3) expression augments the development of regulatory T cells

Regulatory T cells (Tregs) are required for effective immune homeostasis by suppressing harmful immune responses against self-antigens. Transcription factor Foxp3 is required for the development of these cells. How Foxp3 is stabilised and affects Tregs development is still incompletely understood. Previous studies have suggested that hypoxia inducible factor gene HIF-1α negatively influences the development of Tregs and enhances the development of IL-17 producing Th17 cells. In this study, we reveal that prolyl hydroxylase 3 (PHD3), which is a negative regulator of HIF-1α, is upregulated in Tregs and enhances the development of Tregs. The PHD3 inhibitor dimethyl oxalylglycine (DMOG) or siRNAs-PHD3, which upregulates HIF-1α, down-regulated Foxp3 expression, and enhanced the development of Th17 cells. Our observations disclose a novel role of PHD3 in the development of Tregs.