Elsevier Trophoblast Research Award Lecture: Unique properties of decidual T cells and their role in immune regulation during human pregnancy.

Maternal lymphocytes at the fetal-maternal interface play a key role in the immune acceptance of the allogeneic fetus. Most studies focus on decidual NK cells and their interaction with fetal trophoblasts, whereas limited data are available on the mechanisms of fetus specific immune recognition and immune regulation by decidual T cells at the fetal-maternal interface. The aim of this review is to describe the phenotypic characteristics of decidual T cell subsets present at the fetal-maternal interface, their interaction with HLA-C expressed by fetal trophoblasts and their role in immune recognition and regulation at the fetal-maternal interface during human pregnancy.