Tolerating pregnancy

摘要

Pregnancy poses a conundrum for the immune systems of placental mammals. A pregnant female's immune system has to defend both mother and fetus from pathogens, while at the same time tolerating the fetus, which contains antigens that the maternal immune system recognizes as foreign because they are the products of genes inherited from the father. On page 102 of this issue, Rowe et al.1 demonstrate that, during pregnancy, immune cells called regulatory T cells that recognize these paternal antigens proliferate in the mother and specifically suppress the maternal immune response against the fetus. Furthermore, the authors show that a pool of these cells remains long after delivery, facilitating tolerance in subsequent pregnancies. The description of this mechanism may, in the future, help to develop treatments for pre-eclampsia and prevent miscarriages resulting from immune rejection of the fetus.