Abstract
Vascular endothelial cells (ECs) have been demonstrated to play crucial roles in inflammation and immune responses by expressing various adhesion molecules, such as MHC class II antigens, ICAM-1 and ELAM-1 (E-selectin), and by synthesizing various cystokines including IL-1, IFN-γ and TNF. They act as antigen presenting cells in leading to a cascade of immunologic and inflammatory events. The expression of cell adhesion molecules by ECs, particularly high endothelial venules, mediates permeation of lymphocytes and leucocytes in inflammatory lesions, and subsequently leads to continuous inflammation. Both morphological and functional alterations of ECs named “activation” are induced by cytokines in vitro and inflammatory or immune responses, and the concept of endothelial activation is useful in understanding endothelial cell functions. In addition, the immunoperoxidase technique is useful for studying morphological and functional changes of ECs in inflammatory and immune diseases.
