Expression of class II HLA molecules by endothelial cells of human decidua

Many authors have documented a high level of expression of class II HLA molecules by decidua. Although macrophages appear to be responsible for this, we show in this article that endothelial cells (EC) of the venules and capillaries of human decidua also strongly express class II molecules, whereas EC of chorionic villi do not. We discuss this finding in the context of the maternal-fetal immune interaction.