STUDIES OF SKIN-WINDOW EXUDATE HUMAN NEUTROPHILS - COMPLEX PATTERNS OF ADHERENCE TO SERUM-COATED SURFACES IN DEPENDENCE ON FMLP DOSES

Human neutrophils were isolated both from peripheral blood (PB) and fr om aseptic inflammatory exudates obtained by the Senn's skin-window (S W) technique. The respiratory burst (O-2(-) release) and the adherence to serum-coated wells of culture microplates was investigated using a simultaneous assay. Unstimulated PB resting neutrophils did not produ ce a significant amount of O-2(-) and were incapable of adhering to se rum-coated plastic surfaces, while unstimulated SW neutrophils showed augmented adhesion to serum-coated culture wells. SW neutrophils were primed to enhanced FMLP-dependent O-2(-) release in response to n-form yl-methionyl-leucyl-phenylalanine (FMLP). Adhesion of SW neutrophils w as significantly decreased by addition of low doses (10(-10)-10(-8) M) of FMLP (from 17.1% to 8.4%, P < 0.01, N = 12), while fully activatin g doses (>5 x 10(-8) M) of FMLP induced a marked increase of the cell adhesion, more pronounced in SW (39.2%) than in PB cells (27.2%). Low (5 x 10(-9) M) and high (5 x 10(-7) M) FMLP doses induced morphologica l changes (polarization) and actin polymerization in the neutrophils f rom both sources. Biphasic dose-response curves of SW neutrophil adher ence were observed using FMLP, but not using concanavalin A or phorbol myristate acetate as stimulatory agents. Therefore, the adherence of SW cells appears to be regulated in a complex fashion, nonlinearly dep endent on the chemotactic peptide doses and specifically regulated acc ording to the receptors involved.