title: Wheat germ agglutinin specifically inhibits formyl peptide-induced polymorphonuclear leukocyte chemotaxis.
abstract: Evidence that surface membrane glycoproteins of polymorphonuclear leukocytes (PMN) are involved in stimulus-response coupling prompted us to examine effects on these cells of various plant lectins. We have found that wheat germ agglutinin (WGA) (1.0 microgram/ml) completely, specifically, and irreversibly inhibits directed migration (chemotaxis) of human PMN toward the synthetic peptide, N-formylmethionyl-leucyl-phenylalanine (FMLP) (0.1 to 100 nM). This effect of WGA was not shared by subagglutinating concentrations of either concanavalin A or Bandeirea simplicifolia lectin. In contrast to its effects on FMLP-induced chemotaxis, WGA did not influence other FMLP-induced PMN responses (i.e., selective discharge of lysosomal enzymes from cytochalasin B-treated cells, generation of superoxide anion radical(s). WGA also did not influence PMN chemotactic responses to either the complement-derived peptide, C5a, or the lipoxygenase product, leukotriene B4. Inhibition of FMLP-induced chemotaxis by WGA was not reversed by washing WGA-treated cells, but was reversed (and prevented) by N-acetyl-D-glucosamine (not by N-acetyl-D-galactosamine or mannosamine). WGA did not affect either orientation or stimulated random motility of PMN, and did not interfere with specific binding to PMN of (3H)-FMLP. A derivative of WGA with 10-fold less agglutinating activity for human erythrocytes was prepared by treating the native lectin with cyanogen bromide and formic acid. The derivative also inhibited FMLP-induced PMN chemotaxis specifically and selectively. These data suggest that WGA specifically inhibits FMLP-induced PMN chemotaxis by attaching to N-acetyl-D-glucosamine residues at a locus on the PMN plasma membrane that is distinct from the binding site of the FMLP receptor.
mesh_terms: D002634:Chemotaxis, Leukocyte; D006801:Humans; D037102:Lectins / Q000276:immunology*; D008715:Methionine / Q000031:analogs & derivatives*; D009239:N-Formylmethionine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009504:Neutrophils / Q000502:physiology*; D009842:Oligopeptides / Q000037:antagonists & inhibitors*; D011971:Receptors, Immunologic / Q000502:physiology*; D011975:Receptors, Mitogen / Q000502:physiology; D014909:Wheat Germ Agglutinins
chemical_list: D037102:Lectins; D009842:Oligopeptides; D011971:Receptors, Immunologic; D011975:Receptors, Mitogen; D014909:Wheat Germ Agglutinins; C027503:wheat germ agglutinin receptor; D009239:N-Formylmethionine; D009240:N-Formylmethionine Leucyl-Phenylalanine; D008715:Methionine