ANTIBODIES TO POLYSIALIC ACID AND ITS N-PROPYL DERIVATIVE - FINDING PROPERTIES AND INTERACTION WITH HUMAN EMBRYONAL BRAIN GLYCOPEPTIDES

There is no efficient vaccine against group B meningococcal meningitis because of tolerance induced by host tissue polysialic acid cross-rea cting with the capsular polysaccharide. The specificities of polysiali c acid-antibody interactions were studied using a ligand binding assay . Antibodies 735, 20-1, 2-1B, 2-2B, 5E1, and t5E1 and antibodies again st N-propionylated group B meningococcal polysaccharide-tetanus toroid conjugate (NP-4, 106-6) bound polysialylated human embryonal brain gl ycopeptides but not control glycopeptides or disialosyllactose, wherea s antibodies 109-3 and I-627 were more specific for the N-propionylate d polysaccharide. Antiganglioside antibodies (KM538, KM641) did not cr oss-react with polysialic acid. Human class-switched antibodies 5E1 (I gM) and t5E1 (IgG) reacted identically with all compounds tested and n o temperature-dependent differences were observed. All anti-polysialos yl antibodies required a polysaccharide chain of 8-10 residues for bin ding independent of the immunizing antigen, animal species, or immunog lobulin class. The results suggest careful evaluation of polysialic ac id cross-reactivity in vaccine development.