ESTRIOL IN FORMATION OF MONONUCLEAR CELLS TOLEROGENIC FEATURES
Estriol (E3) is one of hormones whose synthesis is mainly associated with pregnancy. The hormone can also regulate immune cells functions. E3 influence on monocyte indoleamine-2,3-dioxygenase (IDO1) activity and Treg and NK cells’ markers expression was investigated. LPS and IFN-γ stimulated IDO1 activity was augmented by Е3 independently of the hormone doses. Both Е3 concentrations increased CD4+Foxp3+ lymphocytes percentage. This hormonal effect was mediated by protein kinase A. CD16 expression upon NK cells was reduced as a result of Е3 influence. The data indicated that Е3 is one of the factors which maintained immune tolerance during pregnancy and protected fetus preservation.