title: Specificity of human anti-NOR antibodies, a distinct species of "natural" anti-alpha-galactosyl antibodies.
abstract: Natural anti-NOR antibodies are common in human sera and agglutinate human erythrocytes of a rare NOR phenotype. The NOR phenotype-related antigens are unique neutral glycosphingolipids recognized by these antibodies and Griffonia simplicifolia IB4 isolectin (GSL-IB4). The oligosaccharide chains of NOR glycolipids are terminated by Galalpha1-4GalNAcbeta1-3Galalpha units. To characterize the specificity of anti-NOR antibodies and compare it with specificities of GSL-IB4 and known anti-Galalpha1,3Gal antibodies, alpha-galactosylated saccharides and saccharide-polyacrylamide conjugates were used. New synthetic oligosaccharides, corresponding to the terminal di- and trisaccharide sequence of NOR glycolipids and the conjugate of the NOR-tri with HSA were included. These compounds were tested by microtiter plate ELISA and hemagglutination inhibition. Anti-NOR antibodies reacted most strongly with Galalpha1-4GalNAcbeta1-3Gal (NOR-tri), and over 100 times less strongly with Galalpha1-4GalNAc (NOR-di). The antibodies reacted also with Galalpha1-4Gal and Galalpha1-4Galbeta1-4GlcNAc, similarly as with NOR-di but not with other tested compounds. In turn, anti-Galalpha1,3Gal antibodies reacted most strongly with Galalpha1-3Gal and were very weakly inhibited by the NOR-related oligosaccharides (weaker than by galactose), and NOR-tri was less active than NOR-di. GSL-IB4 reacted with all tested alpha-galactosylated saccharides and conjugates, including the similarly active NOR-tri and NOR-di. These results showed that anti-NOR represent a new species of anti-alpha-galactosyl antibodies with high affinity for the Galalpha1-4GalNAcbeta1-3Gal sequence present in rare NOR erythrocytes.
authors.affiliation: Department of Immunochemistry, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolf Weigl St 12, 53-114 Wroclaw, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Duk
authors.forename: Ulrika
authors.initials: U
authors.lastname: Westerlind
authors.forename: Thomas
authors.initials: T
authors.lastname: Norberg
authors.forename: Galina
authors.initials: G
authors.lastname: Pazynina
authors.forename: Nicolai N
authors.initials: NN
authors.lastname: Bovin
authors.forename: Elwira
authors.initials: E
authors.lastname: Lisowska
mesh_terms: D000906:Antibodies / Q000276:immunology* / Q000302:isolation & purification; D000918:Antibody Specificity; D000936:Antigen-Antibody Complex / Q000187:drug effects / Q000276:immunology; D001666:Binding Sites, Antibody / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000276:immunology; D006001:Glycoconjugates / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D006023:Glycoproteins / Q000276:immunology; D006386:Hemagglutination Tests; D006801:Humans; D007113:Immunity, Innate; D037102:Lectins / Q000276:immunology; D009844:Oligosaccharides / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014312:Trisaccharides / Q000276:immunology*
chemical_list: D000906:Antibodies; D000936:Antigen-Antibody Complex; D006001:Glycoconjugates; D006023:Glycoproteins; D037102:Lectins; D009844:Oligosaccharides; D014312:Trisaccharides; C076569:alpha-galactosyl epitope