Authors: Benner, Marilen; Feyaerts, Dorien; García, Celia Cartagena; Inci, Nurcan; López, Sergi Cedó; Fasse, Esther; Shadmanfar, Wijs; van der Heijden, Olivier W.H.; Gorris, Mark A.J.; Joosten, Irma; Ferwerda, Gerben; van der Molen, Renate G.
Issue: Cell Rep . 2020 Sep 29;32(13):108204.
Well-timed interaction of correctly functioning maternal immune cells is essential to facilitate healthy placenta formation, because the uterine immune environment has to tolerate the semi-allogeneic fetus and allow adequate trophoblast invasion. Here, we assess the uterine immune signature before and during pregnancy. Extensive supervised and unsupervised flow cytometry clustering strategies not only show a general increase in immune memory throughout pregnancy but also reveal the continuous presence of B cells. Contrary to the belief that B cells are merely a consequence of uterine pathology, decidual B cells produce IL-10 and are found to be localized in clusters, together with Foxp3pos T cells. Our findings therefore suggest a role for B cells in healthy pregnancy.