Saji F, Koyama M, Matsuzaki N
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
Placenta. 1994 Jul;15(5):453-66. doi: 10.1016/s0143-4004(05)80415-1.
Human immunoglobulin G (IgG) Fc receptors are important in the materno-fetal relationship. Three classes of IgG Fc receptors are recognized which generate multiple isoforms, most of which are expressed in different cellular components of human placenta at different times during pregnancy. Although the distinct biological functions of Fc gamma R phenotypes expressed in human placenta are still unknown, recent data provide evidence for an important association between the Fc gamma R phenotype and transcytosis of IgG in the placenta. Selective transfer of maternal IgG across the placenta provides passive immunity to the fetus during the period when its own immune system is gaining protective potential. Furthermore, placenta-specific macrophages may contribute through Fc gamma R-mediated phagocytosis to the protection of the fetus from either infection or maternal immune attack against paternally inherited fetal antigens. Ontogeny and expression of various isoforms of Fc gamma R subtypes may be the key to the elucidation of the transport mechanism of maternal IgG to the fetus, in addition to the determination of the mechanisms of placental protection of the fetus against the maternal immune system.
人免疫球蛋白G（IgG）Fc受体在母婴关系中起着重要作用。已识别出三类IgG Fc受体，它们产生多种异构体，其中大多数在孕期不同时间在人胎盘的不同细胞成分中表达。尽管人胎盘中表达的FcγR表型的独特生物学功能尚不清楚，但最近的数据为FcγR表型与胎盘中IgG的转胞吞作用之间的重要关联提供了证据。母体IgG通过胎盘的选择性转运在胎儿自身免疫系统获得保护潜力的时期为其提供被动免疫。此外，胎盘特异性巨噬细胞可能通过FcγR介导的吞噬作用，保护胎儿免受感染或母体针对父系遗传胎儿抗原的免疫攻击。FcγR亚型各种异构体的个体发生和表达可能是阐明母体IgG向胎儿转运机制的关键，此外还能确定胎盘保护胎儿免受母体免疫系统影响的机制。
