MONOCLONAL-ANTIBODY MODULATES HUMAN NEUTROPHIL CHEMOTAXIS TO N-FORMYL-METHIONYL-LEUCYL-PHENYLALANINE (FMLP)

Utilizing standard hybridoma techniques and a neutrophil chemotaxis as say for screening we produced a mouse monoclonal IgM antibody, 59/4, s elected for specific inhibition of human neutrophil chemotaxis to the N-formyl-methionyl-leucyl-phenylalanine peptide (fMLP). Antibody 59/4 inhibited neutrophil chemotaxis to FMLP, but not human C5a or leukotri ene B4. The antibody exhibited specific homogeneous binding to PMNs, h eterogeneous binding to monocytes, and did not bind to lymphocytes in a pattern similar to the profile of N-formyl peptide binding in flow c ytometric analysis. The antibody did not inhibit the binding of fluore scein-conjugated fMLPK or fML(H-3)P ligands to neutrophils in flow cyt ometric or competitive binding assays. Other neutrophil functions incl uding myeloperoxidase release and rosette formation with immunoglobuli n or immunoglobulin C3b-coated sheep erythrocytes were not affected in the presence of antibody 59/4. These results suggest that 59/4 specif ically inhibits chemotaxis to fMLP.