Granulocytic myeloid-derived suppressor cells expand in cord blood and human pregnancy and modulate T cell responses.

Background Preterm delivery is a leading cause of perinatal morbidity. Reasons are diverse, but immunologic fetal rejection has repeatedly been postulated to be involved. Myeloid derived suppressor cells (MDSC) are myeloid progenitor cells, characterized by their T cell suppressive capacity. They have predominantly been described under pathological conditions like cancer or infectious diseases, yet their role for materno-fetal tolerance remains elusive. We aimed to quantify and characterize MDSC in cord blood (CB) and in pregnancy.