2018 Volume 30 Issue 175 Pages J87-J90
Conjugation of carrier molecules to oligosaccharides has been used as a method to enhance the immunogenicity of oligosaccharides in host animals. Since bovine serum albumin and keyhole-limpet hemocyanin, which are commonly used for peptide antigens, are relatively ineffective for enhancing the immunogenicity of conjugated oligosaccharides, improved methods using streptavidin, non-toxic mutants of the diphtheria toxin and phosphatidylethanolamine have been investigated. Phosphatidylethanolamine can easily be conjugated with the reducing end of oligosaccharides, which is an advantage over other carrier molecules, but the ability to enhance the immunogenicity of the conjugated oligosaccharide has not been fully verified. We found that conjugates of target oligosaccharides and a ceramide analogue, characterized by having a very long-chain fatty acid, could strongly induce the production of antibodies that respond to the target oligosaccharides on glycoproteins and glycolipids in host mice. By using mice immunized with this conjugate, we successfully obtained a monoclonal antibody that recognizes a sialylated oligosaccharide structure found on the major serum glycoproteins, and confirmed the high affinity and strict specificity against its oligosaccharide epitope on the glycoproteins.
