IMMUNOLOGICAL PHENOTYPE OF CULTURED ENDOTHELIAL-CELLS - QUANTITATIVE-ANALYSIS OF CELL-SURFACE MOLECULES

Endothelial cells express a wide spectrum of surface molecules involve d in multiple vascular functions. We quantitatively determined an exte nsive immunologic phenotype of endothelial cells through a large panel of antibodies directed against i) well-known endothelial molecules CD 31, CD34, CD49b, e, f, CD51, CD54, CD55, CD62E and P, CD105, CD106, HL A class I and HLA class II; ii) molecules defined by monoclonal antibo dies newly clustered during the 6th workshop of Human Leukocyte Differ entiation Antigen (HLDA) CD109, CD140b, CD141, CD142, CD143, CD144, CD w145, CD146 and CD147; iii) molecules defined by unclustered monoclona l antibodies. The expression of these molecules was quantified on huma n umbilical vein endothelial cells (HUVEC) cultured in resting conditi ons and after stimulation with IL-1 beta (10 U/ml), TNF-alpha (10 ng/m l) and phorbol myristate acetate (60 ng/ml). Some molecules were const itutively expressed, and others were negative, which served to determi ne the basal phenotype. After cell stimulation, the molecules showed w eak or strong expression modulation, leading to the definition of an a ctivated phenotype. Changes in the kinetics and the amplitude of expre ssion served to characterize poorly defined molecules and may be usefu l to determine their physiologic role. Also, we compared the phenotype s of endothelial cell lines EA.hy 926 and ECV 304 to that of HUVEC to assess their reliability as an endothelial cell model. Each cell line displayed a specific repertoire of molecules expressed at different le vels, which could have significant implications for cell line behavior as endothelial cells.