Uterine DCs are essential for pregnancy.

Successful embryo implantation requires complex interactions between the uterus and embryo, including the establishment of maternal immunologic tolerance of fetal material. The maternal-fetal interface is dynamically populated by a wide variety of innate immune cells; however, the relevance of uterine DCs (uDCs) within the decidua to the success of implantation has remained unclear. In this issue of the JCI, Plaks et al. show, in a transgenic mouse model, that uDCs are essential for pregnancy, as their ablation results in a failure of decidualization, impaired implantation, and embryonic resorption (see the related article beginning on page 3954). Depletion of uDCs altered decidual angiogenesis, suggesting that uDCs contribute to successful implantation via their effects on decidual tissue remodeling, including angiogenesis, and independent of their anticipated role in the establishment of maternal-fetal tolerance.