Successful mammalian pregnancy relies on the action of sophisticated regulatory mechanisms that allow the fetus (a semi-allograft) to grow and develop in the uterus in spite of being recognized by maternal immune cells. Among several immunocompetent cells present at the maternal fetal interface, dendritic cells (DC) seem to be of particular relevance for pregnancy maintenance given their unique ability to induce both antigen-specific immunity and tolerance. Thus, these cells would be potentially suitable candidates for the regulation of local immune responses within the uterus necessary to meet the difficult task of protecting the mother from infection without compromising fetal survival. Current evidence on decidual DC phenotype and function, and their role in the regulation of the maternal immune system during mouse and human pregnancy are discussed and reviewed herein; highlighting novel DC functions that seem to be of great importance for a successful pregnancy outcome.
