Systemic reduction of functionally suppressive CD4dimCD25highFoxp3+ Tregs in human second trimester pregnancy is induced by progesterone and 17β-estradiol

Regulatory T and B Cells in Asthmatic Women: Variations From Pregnancy to Postpartum

“…Progesterone receptors were recently identified in Tregs [27], supporting the immunomodulatory potential of pregnancy hormones. Without compromising the regulatory potential of Tregs during pregnancy, and even promoting their proliferation [28] and proportions [29], progesterone and 17β-estradiol are thought to reduce Foxp3 expression in Tregs in second-trimester pregnant women [30]. Our detection of a decrease in Foxp3 expression during the third trimester of gestation supports and complements these findings.…”

THE ROLE OF THE DIFFERENT SUBPOPULATIONS OF CD4⁺Т LYMPHOCYTES DURING PREGNANCY

“…It should be noted that CD25 is not a molecule, necessary to realize Treg suppressive properties [109]. Treg is characterized by low CD127 expression, reduced CD4 (СD4 dim ), CD45RB low/-expression [78], CD28 expression [109], intracellular CTLA-4 (cytotoxic T lymphocyte antigen) expression [32]. CTLA-4 takes part in restriction of Treg proliferative activity, population homeostasis, and execution of their suppressive properties in respect of effector T lymphocytes [49,109,122].…”

“…According to some data the Treg count in the decidua has no changes from the first to the second trimester [51]. There is also information about Treg count reduction in circulation in pregnant women at the second trimester compared to non-pregnant women [78]. Such significant discrepancy of results may be caused by different cell phenotyping strategies.…”

“…The most important is Treg cell presence in decidua during implantation at early stages of pregnancy, while in the middle and at the end of pregnancy Treg neutralization does not [38,124]. At pregnancy peripheral blood Tregs are noted to have reduced FoxP3 expression, increased CD45RO expression (effector/memory cell marker), and reduced CD45RA expression (naive cell marker), which reflects higher degree of activation of these cells compared to Tregs in non-pregnant women [78]. These alterations may be induced by action of hormones, in particular, progesterone and estradiol [78].…”

“…At pregnancy peripheral blood Tregs are noted to have reduced FoxP3 expression, increased CD45RO expression (effector/memory cell marker), and reduced CD45RA expression (naive cell marker), which reflects higher degree of activation of these cells compared to Tregs in non-pregnant women [78]. These alterations may be induced by action of hormones, in particular, progesterone and estradiol [78]. [17,18,80].…”