title: B cells: the old new players in reproductive immunology.
abstract: Reproductive immunology research has long focused on T cell responses to paternal antigens and tolerance mechanisms supporting fetal well-being. The participation of B cells herein was not widely studied. Because of the fascinating immunological uniqueness of pregnancy, it is however to be expected that such pleiotropic cells play a considerable role. In fact, on the one hand B cells contribute toward pregnancy tolerance by secreting the immunomodulatory cytokine IL-10 but on the other hand can seriously harm pregnancy because of their capacity of producing autoantibodies. As for protective B cells, new evidences in mouse models arise suggesting that IL-10 producing B cells, the so-called B10 cells, help in maintaining tolerance toward semi-allogenic fetal antigens. They may be also important to fight danger signals at the fetal-maternal interface as, e.g., in the case of infections with the aim to restore the disrupted fetal tolerance. In human pregnancies, IL-10 producing B cells increase with pregnancy onset but not in the case of spontaneous abortions. In vitro, they are able to suppress TNF-α production by T cells from pregnant individuals. Their generation and functionality will be discussed throughout this review article. B cells can be deleterious to pregnancy as well. Aberrant B cell compartment is associated with obstetric pathologies. In particular, the capacity of B2 cells to produce specific autoantibodies or of B-1a B cells to secrete natural autoantibodies that can turn autoreactive will be discussed herein.
authors.affiliation: Department of Experimental Obstetrics and Gynecology, Medical Faculty, Otto-von-Guericke University , Magdeburg , Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Fettke
authors.affiliation: Department of Experimental Obstetrics and Gynecology, Medical Faculty, Otto-von-Guericke University , Magdeburg , Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Schumacher
authors.affiliation: University Women's Clinic, Otto-von-Guericke University , Magdeburg , Germany.
authors.forename: Serban-Dan
authors.initials: SD
authors.lastname: Costa
authors.affiliation: Department of Experimental Obstetrics and Gynecology, Medical Faculty, Otto-von-Guericke University , Magdeburg , Germany.
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Zenclussen
keywords: B cells; B10 cells; Breg; IL-10; autoantibodies; pregnancy