title: Recombinant Fc of human IgG1 prepared in an Escherichia coli system escapes recognition by macrophages.
abstract: The Fc portion of IgG is recognized by macrophages via Fc receptors on their cell surface. The recognition of human IgG1-Fc by macrophages was compared for the native and recombinant proteins by a novel assay method using competitive inhibition of the aggregated IgG-mediated chemiluminescence reaction of human macrophage cell line THP-1. Recombinant Fc proteins, prepared in an Escherichia coli system, which lack oligosaccharides and retain normal staphylococcal protein A reactivity and, to a lesser extent, C1q binding capacity, showed inhibitory ability greater than 500 times lower than that of native Fc fragments obtained by proteolytic digestion of myeloma proteins. This suggests that the oligosaccharide chains on IgG1-Fc molecules may be critical for recognition by Fc receptors on macrophages.
authors.affiliation: Department of Pathology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nose
authors.forename: R
authors.initials: R
authors.lastname: Takano
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
authors.forename: Y
authors.initials: Y
authors.lastname: Arata
authors.forename: M
authors.initials: M
authors.lastname: Kyogoku
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002240:Carbohydrate Sequence; D004247:DNA / Q000235:genetics; D004926:Escherichia coli; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000276:immunology*; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology
chemical_list: D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D009844:Oligosaccharides; D011994:Recombinant Proteins; D004247:DNA