35 - MHC and Other Antigens at the Feto-maternal Interface

Abstract

This chapter focuses on the nature of the major histocompatibility complex (MHC) and other antigens that are recognized by the mother in the feto-maternal interface. Throughout most of pregnancy, there is a complicated type of maternal–fetal contact in the placenta, which is formed by fetal (amnion and chorion) and maternal tissues (decidua). The last layer of the placental fetal tissues, which is in contact with the maternal decidua, is trophoblast. The differential expression of HLA-G gene in extraembryonic tissues, which is dependent on the stage of pregnancy and different from that of classical HLA class I genes, implies that it plays an important role at the feto-maternal interface, thus influencing the outcome of pregnancy. R80K is a highly polymorphic protein alloantigen present on the microvesicles prepared from human term placental syncytiotrophoblast, to which the mother produces an immune response. R80K is very immunogenic and covered with antibody in successful pregnancies, as IgG was found to bind it on the syncytiotrophoblast of all term placentas.