The persistence of paternal antigens in the maternal body is involved in regulatory T-cell expansion and fetal-maternal tolerance in murine pregnancy.

IntroductionTolerance of paternal alloantigens without affectinganti-infectious immune responsiveness is the key fora successful pregnancy. However, mechanisms asso-ciated with natural tolerance during pregnancy arefar from being well-known. Somerset et al. proposedregulatory T cells (Treg) as crucial players duringhuman gestation.