Expression of endothelial cell IgG Fc receptors and markers on various cultures.

OBJECTIVE: To determine and compare the expression of endothelial cell IgG Fc receptors (Fc gamma R) and markers on various kinds of cultures.
METHODS: Human breast microvascular endothelial cells (HMVEC), human aortic endothelial cells (HAEC), human umbilical vein endothelial cells (HUVEC) and canine aortic endothelial cells (CAEC) were stimulated with cytokines tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). The binding of anti-Fc gamma receptor (Fc gamma R) type I, II and III antibodies was measured using an enzyme-linked immunosorbent assay (ELISA). The constitutive expression of endothelial cell markers was examined using anti-von Willebrand factor antibodies, Dil-low density lipoprotein (Dil-Ac-LDL) and fluorescein isothiocyanate (FITC)-labeled ulex europaeus agglutinin-1.
RESULTS: The binding of anti-Fc gamma R II was significantly increased by the simultaneous stimulation with TNF-alpha and IFN-gamma on all three types of human endothelial cells (ECs), but not on canine endothelial cells. Enhanced Fc gamma R II expression was most significant when human ECs were cultured in endothelial cell basal medium (ECBM). However, the expression of Fc gamma R II on CAECs could not be induced by human cytokines even after they were cultured in ECBM for 3 passages. Endothelial cells also showed diversity for the constitutive expression of classic markers.
CONCLUSIONS: This study demonstrate that cytokines TNF-alpha and IFN-gamma enhance low-affinity Fc gamma R expression on human endothelial cells in vitro. The results indicate that heterogeneity of endothelial cells exists not only on constitutive expression but also on stimulative expression.