PubMed1983
The reactivity of acquired-B red cells with various antisera has been investigated by agglutination inhibition assays using four trisaccharides obtained by chemical synthesis. Two of these had the structure GalNAc alpha 1-3 (LFuc alpha 1-2). Gal and Gal alpha 1-3 (LFuc alpha 1-2) Gal which are characteristic of the A and B determinants respectively and were indeed strong inhibitors of human anti-A and -B antibodies. The other two sugars denoted B-OAc and B-NH2 are derivatives of the B-trisaccharide by substitution of the hydroxyl group on carbon-2 of the alpha-galactose residue with the O-acetyl group (B-OAc) or the amino group (B-NH2) respectively. We have shown that both B and B-NH2 trisaccharides inhibited strongly the agglutination of acquired B red cells by the anti-B reagents (crude or affinity purified) whereas sera containing "anti-acquired B" agglutinins were specifically inhibited by B-NH2 but not by the A, B or B-OAc structures. We have also shown that the agglutination of Tk-activated erythrocytes by the BS-II lectin is specifically inhibited by N-acetylglucosamine but not by B, B-OAc or B-NH2 structures. These results and the observation that anti-acquired B agglutinins cannot be adsorbed on Tk red cells suggest that (i) the "B-like" and the "acquired-B" determinants share a common structure best represented by B-NH2 and (ii) Tk and "acquired-B" antigens are not identical.