Effect of Estriol, Chorionic Gonadotropin, and Oncostatin M on the Expression of Recombinase RAG-1 in Regulatory T Lymphocyte Subpopulations

: We studied the effect of estriol, chorionic gonadotropin, oncostatin M, and hormone-cytokine combinations on the expression of recombinase RAG-1 in T-regulatory (Treg) and T helper 17 (Th17) lymphocytes. It was found that estriol in a concentration corresponding to the first trimester of pregnancy increased the level of Treg (CD4+FoxP3+) cells and suppressed the formation of Th17 (CD4+RORC+) lymphocytes. This effect was nor observed after individual administration of chorionic gonadotropin and oncostatin M, but some combinations of the studied hormones with oncostatin M increased the percentage of CD4+FOXP3+ cells. In the presence of oncostatin M, the studied hormones enhanced the expression of RAG-1 in CD4+FoxP3+ cells, but not in CD4+RORC+ cells, thereby initiating of Treg T-cell receptor (TCR) revision. The mechanisms of hormone cytokine control of induction of the immune tolerance during pregnancy are discussed.