Open Access

Introduction: For a successful pregnancy, a set of physiological requirements has to be fulfilled. The mother has to provide enough nutrients and the proper anatomical environment for the developing fetus and protect him and herself against pathogens. The cells of the im-mune system constantly monitor the organism in search for pathogens and mount a response to eradicate the threat. The favourable outcome of an immune response re-lays on the capacity of those cells to recognize structures that shouldn’t be present in the organism and the speed or strength at which the cells react. During pregnancy, however, a fetus is able to establish a firm contact with the endometrium of the mother and then grow for an extended period of time. This “exception to the rule” hides behind a set of fine-tuned regulations of the immune responses which are not completely un-derstood. Though many cell types have been extensively investigated in the past dec-ades, B cells play yet enigmatic roles. The aim of this work is to uncover the events occurring within the B cell development during pregnancy and to study the role of certain subtypes in healthy pregnancy and pregnancy miscarriage. Methods: For all experiments, 8-weeks-old female mice either non-pregnant, having normal preg-nancies or miscarriage were used. Organs were removed and cells isolated using standard protocols. The analysis of the population distribution was performed by Flow Cytometry. For in vitro experiments, specific cell subsets were isolated using MACS Cell Separation. Bio-plex method was used for the assessment of Immunoglobulin isotypes in serum, while CBA Array was the method used to measure cytokine levels in the supernatant of cell cultures. Statistical analysis was done using GraphPad Prism software. Results: Pregnancy had a strong impact on the murine B cell development. The restructuration of the B cell compartment could be appreciated already from the bone marrow progeni-tors, reduced in pregnant mice. Peripheral subsets drastically adapted their develop-mental pathways, with a drift towards the generation of marginal zone B cells. B cells also showed functional adaptations to gravidity, as evidenced by the changes in the immunoglobulin production and immunomodulatory capacity. Conclusions: For the first time a deep investigation of the consequences of pregnancy on the B cell development was performed, covering several aspects of B cell functionality. This work shows that B lymphocyte compartment is remodelled during pregnancy. Aberration of this process may lead to pregnancy complications including miscarriage.

In dieser retrospektiven Studie wurden die Schwangerschafts- und Geburtsverläufe von 687 Erstgebärenden mit einer vorherigen früheren zweizeitigen Interruptio mit denen von ebenfalls 687 Primiparen ohne vorausgegangenen Schwangerschaftsabbruch/Abort verglichen. Dabei ließen sich signifikante Unterschiede bei der durchschnittlichen Schwangerschaftsdauer sowie den durchschnittlichen Geburtsgewichten und -körperlängen der Neugeborenen zwischen beiden Gruppen feststellen: Kinder von Frauen mit vorheriger Interruptio waren zum Zeitpunkt der Geburt leichter und von geringerer Körperlänge, die Schwangerschaft endete im Schnitt 2 Tage früher als in der Kontrollgruppe. Ebenso gebaren Frauen mit vorausgegangenem früherem Schwangerschaftsabbruch signifikant öfter Kinder, deren Geburtsgewichte unter der l0. Perzentile lagen. Zu Schnittentbindungen kam es in dieser Untersuchung signifikant häufiger bei Erstgebärenden ohne vorherige Schwangerschaftsunterbrechung. Keine signifikanten, jedoch tendenzielle Unterschiede zeigten sich bei der Frühgeborenenrate, den Kindslagen unter der Geburt, den Raten an hypotrophen Früh- und Neugeborenen sowie beim Auftreten von Plazentastörungen.