Figure 3.

pEXO contribute to maternal tolerance toward the fetus during pregnancy. Exosomes from placenta, syncytiotrophoblast (STB) in particular, support pregnancy via induction of Treg differentiation, restraint of cytotoxic activities of T cells and NK cells, promotion of decidual macrophage polarization, and endowing endothelial cells with viral resistance. Disruption of maternal immune tolerance is associated with adverse pregnancy complications such as miscarriage, preeclampsia. The specific cargoes within the pEXO represent the potential target for prenatal diagnosis and pregnancy-related disease screening.