The effect of mouse uterine decidualization on NK cell distribution and maturation

Objective:To investigate the distribution and regulation of uterine NK cells in mouse uterus during early pregnancy. Methods:Using a unique uNK cell marker,Dolichos biflorus agglutinin (DBA) lectin,to localize NK cells in uterus of normal pregnancy,delayed implantation and artificially induced decidualization. Results:DBA staining is mainly distributed in some vascular endothelial cells during embryo pre-implantation. In D5 of pregnancy after embryo implantation,NK cells were distributed in the stroma of uterine mesometrial pole,with round,immature and small lymphocyte-like cells. During D7 and D8 of pregnancy,the immunostaining results showed that uNK cells were increasingly accumulated in the mesometrial pole of implantation sites,with their morphology changing from small round cells with scattered cytoplasm to large and mature cells with heavy cytoplasmic granules. In the artificially induced decidualization model,the distribution and maturity of NK cells are similar to those of the normal pregnancy in the mouse uteri. Conclusion:The distribution and maturation of uterine NK cells are dependent of uterine decidualization in mouse early pregnancy.