title: Binding characteristics of fluoresceinated Lotus tetragonolobus fucolectin to macrophage populations which are either responsive or refractory to activation by lymphokine.
abstract: Fucose binding protein (FBP) from Lotus tetragonolobus seed was studied by fluorescence microscopy for its binding characteristics to various guinea pig peritoneal macrophage populations. Fluoresceinated FBP (FITC-FBP) was bound optimally at 22 degrees C in a punctate distribution and was internalized at 37 degrees C. Binding of FBP to macrophages was reversed specifically by the competitive sugar L-fucose, and not by D-fucose, L-rhamnose, or D-galactose. FBP was bound with greater frequency and intensity to 3-day oil-elicited peritoneal macrophages which are responsive to migration inhibition by FBP and migration inhibitory factor (MIF) than to resident or 7-day inflammatory macrophages which are unresponsive to activation by the same effectors. Competition for visual binding of FITC-FBP to macrophages was demonstrated by preincubation of cells with unlabeled FBP or MIF. Competition of FITC-FBP binding by MIF was reversed by L-fucose. These results indicate that FBP binds preferentially, with greater frequency and intensity, to macrophage subpopulations which are responsive to MIF than to MIF-refractory macrophages. The data further supports the existence of a common receptor site for MIF and FBP on the macrophage membrane which involves fucosyl determinants.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D019793:Fluorescein; D005452:Fluoresceins; D005643:Fucose / Q000378:metabolism; D006168:Guinea Pigs; D037102:Lectins / Q000276:immunology*; D008262:Macrophage Activation / Q000187:drug effects; D008263:Macrophage Migration-Inhibitory Factors / Q000378:metabolism*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D008297:Male; D009005:Monosaccharides / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism
chemical_list: D005452:Fluoresceins; D037102:Lectins; D008263:Macrophage Migration-Inhibitory Factors; D009005:Monosaccharides; D011971:Receptors, Immunologic; C027112:fucose-binding lectin; C033184:macrophage migration inhibitory factor receptor; D005643:Fucose; D019793:Fluorescein