Abstract

Properties of Uterine Natural Killer Cells in Human Pregnancy, Major Receptors Involved, and Routes of Trophoblast Invasion

Tarek S Beytamouni and Esther Ghanem

Suppression of the maternal immune system to tolerate the fetal alloantigens during implantation translates into an immunological paradox. The initial process of implantation is marked by the migration of interstitial extravillous trophoblast (EVT) into the endometrial wall and is assisted by maternal uterine natural killer (uNK) cells. Any impairment in uNK assistance can ultimately lead to loss of pregnancy. In this review, we discuss current information regarding the role of uNK cells in healthy human pregnancy and their importance in sustaining a controlled invasion of the endometrium by EVT.