Adhesion of Granulocytes to Human Cultured Endothelial Cells

Adhesion is an essential function of the leucocyte in physiological and pathological processes such as bacterial defence, inflammation and possibly thrombosis. We have studied the adhesion (to plastic and to endothelial cells) of normal human granulocytes and granulocyte precursors (promyelocytic leukemia HL 60 cells) at various stages of differentiation. Purified leukocytes were labelled with 51Chromium, and added to confluent human cultured endothelial cells obtained from umbilical veins. The Petri dishes (35 mm) were washed 5 times and the radioactivity measured in each wash. The remaining leukocytes were removed by sodium hydroxide. The effect of increasing concentrations of leukocytes was to linearly increase the adhesion to plastic but did not markedly increase the adhesion to endothelial cells.