B Regulatory Cells: Players in Pregnancy and Early Life

Abstract

Pregnancy and early infancy represent two very particular immunological states. During pregnancy, the haploidentical fetus and the pregnant women develop tolerance mechanisms to avoid rejection; then, just after birth, the neonatal immune system must modulate the transition from the virtually sterile but haploidentical uterus to a world full of antigens and the rapid microbial colonization of the mucosa. B regulatory (Breg) cells are a recently discovered B cell subset thought to play a pivotal role in different conditions such as chronic infections, autoimmunity, cancer, and transplantation among others in addition to pregnancy. This review focuses on the role of Breg cells in pregnancy and early infancy, two special stages of life in which recent studies have positioned Breg cells as important players.

Rituximab, MS, and pregnancy

“…B cells play a broader, yet unclear, role in maintaining or disrupting normal pregnancies. 36 Recent advances in studies of regulatory B-cell populations indicate shifting dynamics during pregnancy. 36 That this could affect repopulation of specific B-cell subsets after prepregnancy B-cell depletion seems plausible, but whether this would result in improved or worsened pregnancy outcomes remains murky.…”

“…36 Recent advances in studies of regulatory B-cell populations indicate shifting dynamics during pregnancy. 36 That this could affect repopulation of specific B-cell subsets after prepregnancy B-cell depletion seems plausible, but whether this would result in improved or worsened pregnancy outcomes remains murky. Future studies examining immunoglobulin levels, B-cell subset repopulation, and pregnancy and neonatal outcomes are needed.…”

PDL1 blockage increases fetal resorption and Tfr cells but does not affect Tfh/Tfr ratio and B-cell maturation during allogeneic pregnancy

“…Besides the old concept that B cells participate in fetalmaternal immune tolerance via attenuating B-cell capabilities characterized by diminished immune responses and reduced auto-antibodies, recent studies have demonstrated that the increased regulatory B cells (Bregs) play an indispensable role in preventing semi-allogeneic rejection and promoting a stable tolerant microenvironment during normal pregnancy [75][76][77][78] . Of particular note, Tfr cells not only regulate GC reaction by inhibiting B-cell maturation, differentiation and antibody production, but also provide IL-10 for Breg-cell proliferation and differentiation 79,80 .…”

The Importance of Vaccinating Children and Pregnant Women against Influenza Virus Infection

“…Differences in immunologic function between young children and adults likely contribute to the increased susceptibility of children to influenza virus infection. The immune system of young children is characterized by a higher frequency of naïve antigen-specific cells [106,107]. This population also tends to have an overall higher number of circulating T and B cells that decreases drastically by six years of age [108].…”