Contribution of CD54 to human eosinophil and neutrophil superoxide production

We have reported that CD54 on eosinophils is involved in eosinophil degranulation. However, the role of CD54 in eosinophil and neutrophil superoxide production is still uncertain. We assessed the effect of CD54 on eosinophils and neutrophils in recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF)- or phorbol myristate acetate (PMA)-induced superoxide production through CD18. Anti-CD54 monoclonal antibody attenuated leukocyte aggregation and superoxide production of rGM-CSF- or PMA-stimulated neutrophils and PMA-stimulated eosinophils. Anti-CD18 monoclonal antibody or theophylline attenuated superoxide production of eosinophils and neutrophils stimulated by either stimuli. Flow cytometric analysis demonstrated CD54 expression on freshly isolated neutrophils but not on freshly isolated eosinophils. CD54 newly expressed on eosinophils reached its peak expression 30 min after PMA stimulation. The increase in CD18 and CD54 expression on neutrophils caused by rGM-CSF stimulation was partially inhibited by theophylline. These data demonstrated that CD54 and CD18 interaction of eosinophils or neutrophils is involved in superoxide production and that the inhibition of superoxide production by theophylline may be at least partly due to the inhibition of CD54 and CD18.