From Treg, FOXP3 to RBPJ: Linking basic science and clinical medicine

The discovery of regulatory T cells (Treg) and Forkhead box protein P3 (FOXP3) gene has unraveled a new venue toward understanding peripheral tolerance and facilitates the development of Treg-based therapy. In this brief review, we introduced the history of discovering Treg and FOXP3, followed by clinical investigations about Treg in several autoimmune diseases, including systemic lupus erythematosus (SLE), ulcerative colitis (UC), and graft-versus-host disease (GVHD). Importantly, Treg abnormality is also found to contribute substantially to recurrent pregnancy loss, repeated implantation failure and preterm birth. We also discussed the role of Epigallocatechin gallate (EGCG) from green tea on Treg's action. Finally, the recent discovery of FOXP3 regulations in the in vitro-induced Tregs (iTreg) by the recombination signal binding protein for Immunoglobulin Kappa J region (RBPJ) gene would be addressed in the context of existing knowledge. In summary, Treg-based therapy can hold significant therapeutic potential for autoimmune diseases, GVHD, recurrent pregnancy loss and repeated implantation failure in the future.