[Transcription factor FOXP3 and reproduction].

Adaptation of the maternal immune response to accommodate the semi-allogeneic fetus is necessary for pregnancy success, and disturbances in maternal tolerance are implicated in miscarriage. FOXP3, a member of the X chromosome-encoded forkhead transcription factor family, is indispensable for the differentiation of regulatory T cells. Regulatory T cells (CD4+ CD25+ FOXP3+ Treg) are pivotal to the maintenance of self-tolerance and the control of immune homeostasis. Many studies show that CD4+ CD25+ FOXP3+ Treg cells are essential for maternal tolerance of the conceptus. Treg cells accumulate in the decidua and are elevated in maternal blood from early in the first trimester. Inadequate expression of FOXP3 is associated with recurrent spontaneous abortion, unexplained infertility and recurrent implantation failure. CD4+ CD25+ FOXP3+ Treg cells offer an attractive target for treatment of auto-immune disease and allograft tolerance and might become a powerful new tool for the treatment of fertility pathologies stemming from disturbances in immune tolerance. This paper reviews the structure, function, expression regulation of FOXP3 and its relation with reproduction.