Andrew Lees - Activation of soluble polysaccharides with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate for use in protein-polysaccharide conjugate vaccines and immunological reagents

Document created by Andrew Lees on Oct 19, 2017
Version 1Show Document
  • View in full screen mode

  Publication Details (including relevant citation   information):

  Vaccine 14:190. 1996

  Lees, A., Nelson, B. L., Mond, J. J.



  Neonates have poor immune responses to type 2 T-cell independent   antigens (TI-2), such as polysaccharides and immunization of   human infants with these antigens does not induce protective   levels of serum antibodies. Conjugating proteins to TI-2 antigens   converts the immune response to one which is T-cell dependent. We   used an organic cyanylating reagent,   1-cyano-4-dimethylaminopyridinium tetrafluroborate (CDAP), to   activate polysaccharides, in water, and subsequently react them   with hexanediamine, in preparation for coupling proteins to the   polysaccharide. CDAP activation of polysaccharide is rapid (<   2 min) and efficient. CDAP can be used to activate   polysaccharides of diverse chemical natures, including dextrans   and pneumococcal types 6, 14, 19 and 23. The critical parameters   in CDAP activation of polysaccharides were the reagent   concentrations and the pH. Activation can be performed over a   broad alkaline pH range, with an optimum of pH 9-10. Furthermore,   proteins can be coupled to CDAP-activated polysaccharides without   the use of a spacer. Direct conjugation of protein to   CDAP-activated polysaccharides can be performed under mildly   alkaline conditions (pH 7-9). These conditions allow CDAP to be   used with alkaline-sensitive polysaccharides and proteins. Mice   immunized with BSA-pneumococcal type 14 polysaccharides (Pn14)   conjugates, prepared either by direct conjugation or via a   spacer, had high anti-Pn14 and anti-BSA serum antibody IgG1   titers, whereas no IgG1 antibody was induced to the unconjugated   components. The ease of use and mild activating conditions should   prove of value in using CDAP to prepare conjugate vaccines, as   well as other immunologically useful reagents.

  Address (URL):