Artificial antigens. Synthetic carbohydrate haptens immobilized on crystalline bacterial surface layer glycoproteins

The crystalline surface-layer glycoproteins of Clostridium thermohydrosulfuricum L111-69, Bacillus stearothermophilus NRS 2004/3a and Bacillus alvei CCM 2051 were used for immobilization of spacer-linked blood group A-trisaccharide (alpha GalNAc(1----3)[alpha Fuc(1----2)]beta Gal) and of the spacer-linked, tumor-associated T-disaccharide [beta Gal(1----3)alpha GalNAc]. The immobilization involved the glycan portions of surface-layer glycoproteins. Different activation methods were used, namely, periodate oxidation, or treatment with epichlorohydrin or divinyl sulfone, followed by coupling of the hapten under appropriate conditions. The resulting conjugates are useful for assessing the application potential of haptenated surface layer preparations as carrier/adjuvants for the induction of immunity to poorly immunogenic molecules.