Regulation of intercellular adhesion molecule-1 expression on endothelial cells with correlation to lymphocyte-endothelial binding.

Intercellular adhesion molecule-1 (ICAM-1) expression on cultured human umbilical cord vein endothelial cells (EC) and its correlation to the leucocyte adherence to EC was investigated. Gamma interferon (IFN-gamma) increases the ICAM-1 expression on EC and concomitantly also increases the binding of leucocytes to EC in vitro. Methylprednisolone down-regulates the IFN-gamma-induced binding, but does not alter the ICAM-1 expression. Leukotriene B4 (LTB4) rapidly increases the binding of lymphocytes to EC, but does not induce ICAM-1 expression on the EC. The dissociation between ICAM-1 expression and leucocyte binding to EC clearly indicates that ICAM-1 is not the only ligand.