TNF-α suppresses regulatory T (Treg) cell function, however the mechanism remains unclear. Here Jingwu Z Zhang and colleagues find that in activated T cells, phosphorylation of FOXP3 promotes its transcriptional activity. TNF-α induces protein phosphatase 1 expression, leading to dephosphorylation of FOXP3 and inhibition of Treg cell function. In individuals with rheumatoid arthritis, TNF-α–specific antibody treatment restores Treg cell activity and FOXP3 phosphorylation, suggesting that post-translational modifications, including phosphorylation, regulate FOXP3 activity and Treg cell–mediated suppression.
- Hong Nie
- Yingxia Zheng
- Jingwu Z Zhang
