The regulatory roles of decidual glycodelin-A on trophoblast and immune cell functions during early pregnancy

Abstract

Placenta is a potential target for maternal immunological attack. Many mechanisms have evolved to suppress the maternal immune response during pregnancy. For example, the decidua has a high degree of specialization of its resident leukocyte populations. Decidual natural killer cells and macrophages are the 2 major cell types of the maternal‐fetal interface. These decidual leukocytes play critical roles on regulating maternal immune tolerance through their interaction with each other and trophoblastic cells. They also contribute to promote placental development at the maternal‐fetal interface. Glycodelin‐A is the major glycoprotein found in the human decidua during early pregnancy. It plays an important role in placental development and feto‐maternal defense. Glycodelin‐A interacts by its unique carbohydrate side‐chains with the cell surface of various cell types in the human feto‐maternal interface, particularly the immune cells, and modulates their functions and differentiation to permit successful pregnancy. Abnormal levels of glycodelin‐A in the endometrium, uterine flushings and/or maternal serum correlate with unexplained infertility, preeclampsia, early pregnancy loss and recurrent miscarriage. This presentation integrates recent studies and our new findings on the roles of decidual glycodelin‐A in placental development and fetomaternal tolerance during early pregnancy. Further insight into the biological properties of glycodelin‐A and its glycosylation will provide better understanding of its molecular nature and biological role, and thus offer opportunities for developing new prevention and/or treatment strategies for pregnancy complications.