Analysis of CD157 expression. (A) Flow cytometric analysis of the surface expression of CD157, CD54, and CD31 on HUVECs. Gray-filled profiles are the isotype-control mAb. Number of events was 10 000. Results are representative of 5 experiments. (B) Confluent HUVEC monolayers were stained and the expression of CD157, CD54, and CD31 analyzed by laser-scanning confocal microscopy. Cells were imaged using a ×60/1.4 numerical aperture (NA) oil immersion objective. Bar represents 30 μm. (C) Western blot of PMN and HUVEC lysates probed with anti-CD157 mAb. (D) Surface expression of CD157 and CD54 (used as a control) was assessed by flow cytometry on HUVECs treated with selected cytokines and chemical mediators for the times indicated. Number of events was 10 000. The difference between control and treated cells was calculated as: fold difference = treated cells (MFI [anti-CD157 or -CD54] – MFI negative control)/(MFI [anti-CD157 or -CD54] – MFI negative control) in the untreated cells. Results are expressed as mean ± SD of 3 experiments. *P < .05, **P < .001.