Differential Distribution of CD4+CD25bright and CD8+CD28− T-cells in Decidua and Maternal Blood During Human Pregnancy

Choriodecidual leukocytes display a unique gene expression signature in spontaneous labor at term

“…These results coincide with previous studies demonstrating that choriodecidual leukocytes express CAMs [16,39,40], cytokines [8,41,42], chemokines [16,34], and their receptors [16,34,43], enzymes [35,44,45], antimicrobial peptides [46], markers of activation [17,39,[47][48][49], and even hormone receptors [50] before and during the process of labor. Together, these findings demonstrate that the choriodecidual leukocytes are a rich source of inflammatory mediators that can participate in the proinflammatory milieu that accompanies the process of labor.…”

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

“…The observed reduction in circulating Tregs could in fact be a consequence of a local recruitment to the decidua/placenta where Tregs seem enriched (20) and ought to have a more obvious role in protecting the fetus against detrimental immune reactions. During the writing of this manuscript, Tilburgs and colleagues reported that fetusspecific Treg cells could only be found at the fetal-maternal interface (45), whereas we previously found indications of fetus-specific Tregs in the circulation (18).…”

“…However, the importance of Tregs in maintenance of human pregnancy in vivo is far from settled. Studies in humans have suggested that there is an increase in the CD4 + CD25 high population during normal pregnancy, most apparently at the fetal-maternal interface (19)(20)(21) but also in the circulation (19,(21)(22)(23).…”

Immune cells in the placental bed

“…Both Sasaki et al (2004) and Yang et al (2008) reported an increased percentage of CD25bright cells in the decidual CD4+ population in early pregnancy, compared with that in the peripheral blood CD4+ population from the same subjects, although the proportions of CD25bright cells that were detected differed between the two studies. A greater proportion of CD4+CD25+ cells have been identified in decidua parietalis compared to decidua basalis in both early pregnancy and at term (Tilburgs et al, 2006). CD8+CD28+ T regulatory cells have also been identified in decidua from early pregnancy and term using flow cytometry (Tilburgs et al, 2006).…”