Time course of DAF upregulation on HUVECs and DMECs by cytokines. EC monolayers were stimulated for up to 72 hours with plain medium or a combination of TNF- (10 ng/mL) and IFN-γ (500 U/mL). After harvesting, single-cell suspensions were analyzed by flow cytometry for DAF expression using MoAb 5B2. (A) Upregulation of DAF on DMECs and HUVECs after 48 hours of stimulation with a combination of TNF- and IFN-γ: negative control (…), constitutive expression of DAF (—), and TNF- and INF-γ–induced DAF (filled histograms). (B) Kinetics for DAF expression on DMECs and HUVECs following stimulation with TNF- and IFN-γ. The figure is representative of 3 similar experiments on each cell type.