Progestogens and Immunology“

Publication date: Available online 5 July 2019Source: Best Practice & Research Clinical Obstetrics & GynaecologyAuthor(s): J. Szekeres-Bartho, E. Schindler A.AbstractFifty per cent of fetal antigens are of paternal origin. These are recognized by the maternal immune system, resulting in lymphocyte activation and the induction of progesterone receptors in immune cells. Upon progesterone binding a downstream mediator called the progesterone induced blocking factor (PIBF) is produced. The full length PIBF is a 90 kDa protein, however, due to alternative splicing, several smaller isoforms are also produced. While the 90 kDa molecule plays a role in cell cycle regulation, the small isoforms are localized in the cytoplasm, and after being secreted, bind to their receptors on other cells, and act in a cytokine-like manner. The communication between the embryo and the maternal immune system is established via PIBF containing extracellular vesicles. PIBF induces an increased production of Th2 cytokines, and inhibits degranulation of NK cells, and by regulating the maternal immune response, contributes to successful implantation and the maintenance of pregnancy.
Source: Best Practice and Research Clinical Obstetrics and Gynaecology - Category: OBGYN Source Type: research