title: Monoclonal antibodies PMN 6, PMN 29, and PM-81 bind differently to glycolipids containing a sugar sequence occurring in lacto-N-fucopentaose III.
abstract: Three monoclonal antibodies, PMN 6, PMN 29, and PM-81, bind myeloid cells. Antibodies PMN 6 and PMN 29 bind specifically to granulocytes but differ in their ability to bind some other cell lines [E. D. Ball, R. F. Graziano, L. Shen, and M. W. Fanger (1982) Proc. Natl. Acad. Sci. USA 79, 5374-5378]. Antibody PM-81, in addition to granulocytes, also binds to eosinophils, monocytes, and most acute myelocytic leukemia cells [E. D. Ball, R. F. Graziano, and M. W. Fanger (1983) J. Immunol. 130, 2937-2941]. Despite these differences, the binding of all three antibodies to cells was inhibited by the oligosaccharide, lacto-N-fucopentaose III [Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc]. Solid-phase radioimmunoassays using purified glycolipids containing sugar sequences found in lacto-N-fucopentaose III demonstrated different binding characteristics for each antibody. PM-81 bound lower concentrations of glycolipids than PMN 29, while PMN 6 required the highest concentration of glycolipids for binding. Autoradiography of thin-layer chromatograms of glycolipid antigens supported these results. The binding of these monoclonal antibodies to cells probably depends on the density of antigens on the cell surface, each antibody requiring a different density. Thus, cells containing antigen below a certain threshold concentration may not bind low-affinity antibodies.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000915:Antibody Affinity; D000918:Antibody Specificity; D001345:Autoradiography; D001666:Binding Sites, Antibody; D002240:Carbohydrate Sequence; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D016256:Lewis X Antigen / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology; D009844:Oligosaccharides / Q000276:immunology*; D011863:Radioimmunoassay
chemical_list: D000911:Antibodies, Monoclonal; D006017:Glycolipids; D016256:Lewis X Antigen; D009844:Oligosaccharides