Petroff M G, Chen L, Phillips T A, Hunt J S
Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
Placenta. 2002 Apr;23 Suppl A:S95-101. doi: 10.1053/plac.2002.0813.
The placenta utilizes both active and passive mechanisms to evade rejection by the maternal immune system. Recently, the mRNA for two newly cloned members of the B7 family of immunomodulatory cell-associated proteins have been identified in the human term placenta. In this article, we review the current knowledge of the B7 family member B7-H1, and discuss how it may participate in modulation of the maternal immune system at the maternal-fetal interface. B7-H1 has been found to possess immunostimulatory or immunoinhibitory properties, and immunohistological examination of first trimester and term placenta has revealed that this protein is abundant in the placenta. B7-H1 is highly expressed by both the syncytiotrophoblast and extravillous cytotrophoblast, both of which lie in direct contact with maternal blood and tissue. Further, treatment of the choriocarcinoma cell line, JEG-3, with recombinant human interferon (IFN)-gamma resulted in a dose-dependent increase in the abundance of the message for B7-H1, suggesting that IFN-gamma could regulate expression of B7-H1 by the trophoblast. These studies document that the positioning of B7-H1 at the maternal-fetal interface is such that it could participate in suppression of activated maternal leukocytes.
胎盘利用主动和被动机制来逃避母体免疫系统的排斥。最近，在人类足月胎盘中发现了免疫调节细胞相关蛋白B7家族两个新克隆成员的信使核糖核酸。在本文中，我们综述了关于B7家族成员B7-H1的现有知识，并讨论了它可能如何在母胎界面参与调节母体免疫系统。已发现B7-H1具有免疫刺激或免疫抑制特性，对孕早期和足月胎盘的免疫组织学检查显示该蛋白在胎盘中含量丰富。B7-H1在合体滋养层细胞和绒毛外细胞滋养层细胞中均高度表达，这两种细胞均与母体血液和组织直接接触。此外，用重组人干扰素（IFN）-γ处理绒毛膜癌细胞系JEG-3，导致B7-H1信使核糖核酸丰度呈剂量依赖性增加，提示IFN-γ可调节滋养层细胞对B7-H1的表达。这些研究证明，B7-H1在母胎界面的定位使其能够参与抑制活化的母体白细胞。
