Simultaneous analysis of peripheral blood granulocytes, lymphocytes, and monocytes adhering to human microvascular endothelial cells.

We describe a sensitive, reliable, and convenient procedure to assay cell adhesion based on flow cytometry which allows quantitative studies of all major peripheral blood leukocytes adhering to microvascular endothelial cells. Using this assay, we show that adhesion of mononuclear cells is significantly increased in the presence of granulocytes and that maximal quantitative adhesion of lymphocytes and monocytes requires 30-40 min compared to 5-10 min required for maximal granulocyte adhesion. Moreover, we demonstrate peripheral blood leukocytes from different healthy individuals displayed considerable variations in efficiency of adhesion to pooled microvascular endothelial cells. The here-described methodology may provide a useful tool to characterize the impact of defined mediators or pharmacological agents on stable cell-cell adhesion of peripheral blood leukocytes to microvascular endothelial cells. Moreover, it may hell to identify interindividual variations in cell adhesion efficiency relevant to cell-mediated immune reactions.