Fig. 3From: The regulation of ovary and conceptus on the uterine natural killer cells during early pregnancyThe regulation of ovary and conceptus on the uNK cells. In early pregnancy, endocrine signaling (e.g. estrogen and progesterone) of ovarian cells can regulate recruitment, proliferation, differentiation and function of uNK cells via direct action on intracellular nuclear receptors (e.g.ERRβ, GR) or through intermediary cells in the surroundings (e.g. T lymphocytes and endometrial stromal cells). Compared to ovaries, besides endocrine signaling (e.g. hCG), conceptus also utilizes juxtacrine signaling (e.g. HLA-C) and paracrine signaling (e.g. cytokines) to facilitate activities above of uNK cells. In addition, under the influence of ovarian hormones, conceptus can increase expression of PIBF and HLA-G molecules to reduce cytotoxicity of uNK cells and promote angiogenesisBack to article page