Subcellular Location of Neutrophil Opsonic Receptors Is Altered by Exogenous Reactive Oxygen Species

The effect of exposure of PMN to extracellular oxidants on the PMN oxidative burst on the subcellular location of CD64 (FcγRI), CD32w (FcγRII), CD16 (FcγRIII), CD35 (complement receptor 1), and CD11b/CD18 (complement receptor 5) was studied. Incubation of PMN with glucose/glucose oxidase resulted in an intracellular shift in Fcγ receptors from secretory vesicles to plasma membrane fractions while reducing complement receptor expression in plasma membrane fractions. Incubation of PMN with xanthine/xanthine oxidase resulted in an intracellular shift in Fcγ receptors from specific granules to secretory vesicles. Incubation of PMN with xanthine/xanthine oxidase resulted in an intracellular shift from secretory vesicles to plasma membrane fractions for CD35 and from secretory vesicles and specific granules to plasma membrane fractions for CD11b/CD18. The effects of glucose/glucose oxidase and xanthine/xanthine oxidase on receptor redistribution were blocked by catalase and catalase and superoxide dismutase, respectively. Cytoskeleton stabilization with phalloidin and Taxol blocked the effect of glucose/glucose oxidase and xanthine/xanthine oxidase on Fcγ and complement receptor relocation. Both H-7 and staurosporine abrogated the effect of glucose/glucose oxidase and xanthine/xanthine oxidase on Fcγ receptor relocation, while genistein abrogated the effect of glucose/glucose oxidase and xanthine/xanthine oxidase on complement receptor relocation. Increases in CD64, CD32w, CD16, CD35, and CD11b/CD18 expression associated with plasma membrane fractions corresponded to functional increases in monomeric IgG binding, E-IV.3, (sheep erythrocyte opsonized with monoclonal antibody IV.3 directed against CD32w) E–Con A, EC3b, and EC3bi rosetting. These studies indicate that exposure of PMN to extracellular oxidants does not occur as an isolated event but results in a coordinated subcellular relocation of opsonic receptors which corresponds to changes in PMN function.