FcRn, but not FcγRs, drives maternal-fetal transplacental transport of human IgG antibodies

Abstract

The IgG Fc domain has the capacity to interact with diverse types of receptors, including FcRn and FcγRs, which confer pleiotropic biological activities. Whereas FcRn regulates IgG epithelial transport and recycling, Fc effector activities, such as ADCC and phagocytosis are mediated by FcγRs, which upon crosslinking transduce signals that modulate the function of effector leukocytes. Despite the well-defined and non-overlapping functional properties of FcRn and

Medical therapy to attenuate fetal anaemia in severe maternal red cell alloimmunisation

“…Expressed by the placental syncytiotrophoblast, FcRn transports maternal IgG subtypes across the placenta, by transcytosis, into the fetal circulation 21 . This transplacental transference is dependent upon: (i) the maternal level of total IgG and specific antibodies; (ii) gestational age of the pregnancy; (iii) placental ‘integrity’; (iv) IgG characteristics including the subclass and degree and type of glycosylation; 22 and (v) the nature of the antigen (being more intense for thymus‐dependent ones). It is also possible that pregnancy‐related pathology itself may affect this process 23 .…”