Abstract
This investigation was conducted to detect Fcgamma receptors (FcgammaR) on cytokine-stimulated human endothelial cells (EC) by measuring anti-FcgammaR MoAb binding with an ELISA. TNF-alpha and IFN-gamma significantly increased the expression of FcgammaR type II (FcgammaRII) and type III (FcgammaRIII) on aortic EC. Simultaneous treatment with both cytokines had a synergistic effect and pretreatment of EC with IFN-gamma augmented the effect of TNF-alpha. The greatest effect was the increase (up to four-to-six-fold) in expression of FcgammaRII found by the simultaneous treatment of aortic EC with both cytokines. The receptors were expressed on the cell surface and showed receptor capping after incubation at 37 degrees C. This study showed that the inflammatory cytokines TNF-alpha and IFN-gamma enhanced low-affinity FcgammaR expression on human EC in vitro. The expression of FcgammaR may contribute to the specific localization of circulating immune complexes on blood vessels in areas of vasculitis.