Relationships between female reproductive performance and uterine natural killer (uNK) cells were investigated in pregnant IL-2 receptor β-chain overexpressed transgenic (Tg2R β) mice. At 8 days of pregnancy, all fetuses were alive, suggesting that implantation normally occurred in these mice. However, 47% of fetuses were dead at 10 days of pregnancy and at 12 days all fetuses were resorbing, indicating that fetal loss progressed with the advance of pregnancy. The placenta of Tg2Rβ mice gradually decreased in weight with the advance of pregnancy. At 10 days the placental labyrinth, decidua basalis, and metrial gland in Tg2Rβ mice were poorly developed, and more uNK cells were found in Tg2Rβ mice than in the control mice. We propose that Tg2Rβ mice are the first and interesting model that uNK cells can cause abortion, to clarify the involvement of uNK cell function in female reproductive performance.
Journal of The Japanese Society of Veterinary Science