Differing reactions of monoclonal anti-A antibodies with oligosaccharides related to blood group A.
Inhibition radioimmunoassays with blood group A-related oligosaccharides have been used to investigate the specificities of six monoclonal anti-A antibodies, three of which had been intentionally generated by immunization of mice with blood group A erythrocytes and A-active blood group substance, and three were incidentally produced following immunization of mice with human tonsil cell membranes or a human colon cancer cell line. By hemagglutination, these antibodies are highly specific for human blood group A erythrocytes. However, they differ from one another in their reaction patterns with mono- and difucosyl A antigen structures and the corresponding afucosyl sequences on Type 1 and Type 2 backbone structures. The six antibodies, together with four previously characterized anti-A monoclonal antibodies (originally raised against the receptor for epidermal growth factor) have been classified into five groups. The first two groups consist of antibodies with broad specificities for A-related structures. There are five antibodies in the first group (TL5, 29.1, A17/3D1, MH2/6D4, and MH1/5D1) reacting to varying degrees with the mono- and difucosyl A antigen structures on either type of backbone sequence. In the second group are two antibodies (A15/3D4 and A15/3D3) which are difficult to inhibit with the oligosaccharides tested, but they reacted best with monofucosyl A structure on either type of backbone. Each of the remaining three antibodies had a distinct and more restricted reaction pattern, with a specificity for the difucosyl A antigen on both types of backbone (antibody EGR/G49) or the Type 1-based mono- and difucosyl A antigen structures (antibody MAS 016c) or the Type 2-based monofucosyl A antigen structure (antibody 455). The reactions of four of the antibodies with N-acetylgalactosamine or with oligosaccharides containing the afucosyl sequence GalNAc alpha 1-3Gal suggest that they may react with certain glycoconjugates with alpha-N-acetylgalactosaminyl termini ("A-like" structures) that are unrelated to the products of the blood group A gene-specified alpha-N-acetylgalactosaminyl-transferase. Knowledge of the differing reactions of these monoclonal antibodies is important for interpreting their reactions with glycoproteins and glycolipids of diverse origins.
H C
HC
Gooi
E F
EF
Hounsell
J K
JK
Picard
A D
AD
Lowe
D
D
Voak
E S
ES
Lennox
T
T
Feizi
D000017:ABO Blood-Group System / Q000276:immunology*; D000116:Acetylgalactosamine / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D002462:Cell Membrane / Q000276:immunology; D003110:Colonic Neoplasms / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D005643:Fucose / Q000276:immunology; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007114:Immunization; D051379:Mice; D009844:Oligosaccharides / Q000276:immunology*; D014066:Palatine Tonsil / Q000276:immunology; D011863:Radioimmunoassay
D000017:ABO Blood-Group System; D000911:Antibodies, Monoclonal; D000939:Epitopes; D009844:Oligosaccharides; D005643:Fucose; D000116:Acetylgalactosamine