ABSTRACT: Carbohydrate sequences occur in both glycolipids and glycoproteins on all cell surfaces and on excreted glycoconjugates such as mucins. These oligosaccharide sequences change during development and in adults constitute antigens responsible for many of the heritable blood groups. During tumorigenesis of a particular tissue, glycosylation may revert to an earlier developmental form found in foetal precursor cells. As these structures are immunogenic, many cancer-associated antigens defined by monoclonal antibodies are oligosaccharides. In this study, antibodies submitted to the lung cancer workshop were screened by an enzyme-linked immunoassay for binding to synthetic glycoproteins produced by coupling chemically-defined oligosaccharide haptens to either bovine or human serum albumin. The 34 different synthetic glycoproteins that were screened contain the following carbohydrate structures: ‘T-antigen’, lactose, melibiose, maltose, cellobiose, 2?-fucosyllactosamine, globotriose, A-trisaccharide, B-trisaccharide, chitotriose, 3?-sialyllactose, 6?-sialyllactose, Man?1-3Man?1-4(GlcNAc), Ley-tetrasaccharide, gangliotetraose, lacto-N-tetraose, lacto-N-neotetraose, A-tetrasaccharide, globotetraose, Man?1-2Man?1-3Man?1-4(GlcNAc), lacto-N-fucopentaose I, lacto-N-fucopentaose II, lacto-N-fucopentoase III, sialyllacto-N-tetraose a, sialyllactotetraose b, sialyllacto-N-neotetraose c, lacto-N-difucohexaose I, lacto-N-hexaose, lacto-N-neohexaose, sialyllacto-N-fucopentaose II, sialyllacto-N-fucopentaose III, disialyllacto-N-tetraose, A-heptasaccharide and bi-antennary octasaccharide. Of the 99 antibodies submitted to the workshop, 14 bound at least one of these oligosaccharides (Table I). By comparing the binding specificities of the antibodies to different but structurally similar carbohydrates sequences, a detailed epitope map is defined for each carbohydrate-binding antibody.
