Characterization of mac25/angiomodulin expression by high endothelial venule cells in lymphoid tissues and its identification as an inducible marker for activated endothelial cells.

Previous results have indicated that mac25/angiomodulin (AGM) is expressed in lymph node (LN) high endothelial venules (HEV), the specialized venules that support efficient lymphocyte transendothelial migration. How mac25/AGM's endothelial expression pattern is regulated in situ remains unknown. Here, we demonstrate that in mouse LN blood vessels, including HEV, mac25/AGM is localized, unlike previous reports, not to the luminal or lateral regions bordering the endothelial cells (EC), but exclusively to the basal lamina that is in direct association with EC.