Adhesion attenuates respiratory burst induced by different modes of triggering in resting or LPS-primed neutrophils

Abstract

The effects of adherence on neutrophil superoxide anion (O2−) generation triggered by surface, soluble ligand, or adherence were studied. Resting-neutrophils adhered to the uncoated tubes resulting in O2− generation, but not on plasma-, fibrinogen-, vitronectin-, fibronectin-, laminin-, collagen-, or poly HEMA-coated surfaces. Enhanced N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated O2− generation by LPS-primed-neutrophils was induced by the incubation on plasma, fibrinogen, vitronectin, fibronectin, or laminin in the absence of Mg2+. In the presence of Mg2+, this response was observed in cells on collagen or poly HEMA. LPS-primed-neutrophils adhered to uncoated, BSA- or IgG-coated tubes and did not respond to fMLP, indicating that the fMLP-response of LPS-primed-neutrophils was suppressed by adherence.Upon incubation on plasma, fibrinogen, vitronectin, fibronectin in the presence of Mg2+, LPS-primed-neutrophils showed O2− generation. Upon incubation on collagen or poly HEMA, the primed-neutrophils neither generated O2− nor adhered. We found that O2− response of LPS-primed-neutrophils was attenuated depending on the time of exposure to plasma-coated surface. This attenuation was evident on plasma or fibrinogen, but not on collagen in the presence of Mg2+, indicating that O2− generation by LPS-primed-neutrophils was attenuated dependent on adherence but not on Mg2+. Thus, adhesion attenuated the O2− generation triggered by both soluble (fMLP) and insoluble (surface) stimuli.