MONOCLONAL-ANTIBODIES DIRECTED TO THE SYNTHETIC CARBOHYDRATE ANTIGEN LE(Y)

Tetrasaccharide Fuc alpha 1-2Gal beta 1-4(Fuc alpha 1-3)GlcNAc is know n as carbohydrate determinant of cancer- and AIDS-associated antigen L ewis(y) (Le(y)). Synthetic antigen to generate mouse monoclonal antibo dies (MAbs) directed to Le(y) was prepared and constructed as a spacer -armed tetrasaccharide coupled with lipophilized polymer, Le(y)-PAA-PE , where PAA is a 30-kD polyacrylamide and PE is phosphatidylethanolami ne, An efficient immune response was provided by using Le(y)-PAA-PE ad sorbed on Salmonella minnesota. Positive hybridomas were screened by e nzyme-linked immunosorbent assay (ELISA) using Le(y)-PAA as a coating agent. An inhibitory version of the same test system showed absolute s pecificity of two MAbs: only hapten Le(y) and Le(y)-PAA were strong in hibitors, in contrast to Le(b), tri- and disaccharidic fragments of th e mentioned tetrasaccharides, as well as their PAA-conjugates. MAbs ob tained against synthetic antigen specifically stained the Le(y) (+) ce ll line A431.