[Monocyte chemotactic factor produced by human umbilical vein endothelial cells in vitro]

The blood monocytes have been well known as one of the origins of foam cells in atherosclerotic plaque, but the mechanism controlling the migration of monocytes into the subendothelial space is still unclear. The chemotactic activity of the conditioned medium from cultured human umbilical vein endothelial cells for human blood monocytes was investigated by micropore filter assay; meanwhile, heat stability and enzyme digestion assays were undertaken. The results showed that the conditioned medium from the cultured endothelial cells was significantly chemotactic rather than chemokinetic for monocytes. The conditioned medium from the cultured endothelial cells still retained the chemotactic activity for monocytes although it was heated at 80C and 100C for 15 min respectively, whereas after digestion with protease, the chemotactic activity vanished. From the above-mentioned facts, it is reasonable to believe that cultured human umbilical vein endothelial cells can secrete a chemotactic factor for monocytes, which is a kind of peptide.