Previous Article | Next Article ![]()
Clinical and Vaccine Immunology, August 2006, p. 936-943, Vol. 13, No. 8
1071-412X/06/$08.00+0 doi:10.1128/CVI.00122-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.
Arun Sarkar,
Anello J. D'Ambra,
Maryline Laude-Sharp,
Samuel Moore,* and
Peter C. Fusco
BioVeris Corporation, Gaithersburg, Maryland 20877
Received 30 March 2006/ Returned for modification 16 May 2006/ Accepted 30 May 2006
Recent efforts toward developing vaccines against group B streptococci (GBS) have focused on increasing the immunogenicity of GBS polysaccharides by conjugation to carrier proteins. However, partial depolymerization of GBS polysaccharides for the production of vaccines is a difficult task because of their acid-labile, antigenically critical sialic acids. Here we report a method for the partial depolymerization of type II and III polysaccharides by mild deaminative cleavage to antigenic fragments with reducing-terminal 2,5-anhydro-D-mannose residues. Through the free aldehydes of their newly formed end groups, the fragments were conjugated to tetanus toxoid by reductive amination. The resulting conjugates stimulated the production in animals of high-titer type II- and III-specific antibodies which induced opsonophagocytic killing of type II and III strains of group B streptococci. For the type II conjugates, immunogenicity increased as oligosaccharide size decreased, whereas for type III conjugates, the size of the oligosaccharides did not significantly influence immunogenicity. When oligosaccharides of defined size were conjugated through sialic acid residues, the resulting cross-linkages were shown to affect immunogenicity. When oligosaccharides were conjugated through terminal aldehyde groups generated by deamination, modification of the exocyclic chain of sialic acid did not influence immunogenicity.
Present address: NABI, Research and Development, 12276 Wilkins Avenue, Rockville, MD 20852.
Present address: Glycomimetics, 101 Orchard Drive, Gaithersburg, MD 20878.
Present address: Novartis Knowledge Center, East Hanover, NJ 07936.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»