Analysis of DAF, CD59, and MCP expression on DMECs and HUVECs following stimulation with cytokines. Monolayers of ECs were incubated for 48 hours in the presence or absence of IL-1β (10 ng/mL), IFNγ (500 U/mL), TNF- (10 ng/mL), or TNF- and IFN-γ before harvesting and analysis by flow cytometry. DAF, CD59, and MCP were detected using MoAbs 5B2, A35, and TRA-2-10, respectively. The results (mean ± SD) are expressed as the RFI (MFI of test sample divided by MFI of irrelevant isotype-matched negative control) for (A, B) DAF, (C, D) CD59, and (E, F) MCP. The results are representative of 4 experiments performed on different EC lines. *P < .05, **P < .02. The efficacy of cytokines used in each experiment was confirmed by their ability to induce VCAM-1 or ICAM-1 as appropriate (data not shown). US, unstimulated.