Carbohydrate structures, in the form of capsular polysaccharides (CPSs) or lipopolysaccharides
(LPSs), are important surface antigens of bacteria and accordingly of interest for serotyping of
and as vaccines against bacteria. The successful introduction of glycoconjugate vaccines, i.e.,
saccharide structures conjugated to a carrier protein, has dramatically increased the interest in
this type of vaccines. There are now efficacious commercial glycoconjugate vaccines against
Haemophilus influenzae type b, Neisseria menigitidis type c and Streptococcus pneumoniae
(seven serogroups), all based on partly hydrolyzed native capsular polysaccharide structures.
However, it is sometimes difficult to use native bacterial polysaccharides due to, e.g.,
heterogeneity, instability, toxicity or molecular mimicry of these structures. An interesting
alternative is then synthetic well-defined oligosaccharide part structures or analogues. Owing
to the fast progress in oligosaccharide synthesis during the last years the synthesis of these
often most complex structures has become feasible. Syntheses of a number of complex
oligosaccharides corresponding to structures, both CPS and LPS, from the microbes
Haemophilus influenzae, Neisseria meningitidis, and Cryptococcus neoformans, including
synthetic challenges like seven and eight carbon sugars and various phosphate diester groups
(both as substituents and anomerically linked), will be presented, as well as their conjugation to
carrier proteins and evaluation as vaccine candidates.
Stefan Oscarson,
Centre for Synthesis and Chemical Biology, University College Dublin,
Belfield, Dublin 4, Ireland
(LPSs), are important surface antigens of bacteria and accordingly of interest for serotyping of
and as vaccines against bacteria. The successful introduction of glycoconjugate vaccines, i.e.,
saccharide structures conjugated to a carrier protein, has dramatically increased the interest in
this type of vaccines. There are now efficacious commercial glycoconjugate vaccines against
Haemophilus influenzae type b, Neisseria menigitidis type c and Streptococcus pneumoniae
(seven serogroups), all based on partly hydrolyzed native capsular polysaccharide structures.
However, it is sometimes difficult to use native bacterial polysaccharides due to, e.g.,
heterogeneity, instability, toxicity or molecular mimicry of these structures. An interesting
alternative is then synthetic well-defined oligosaccharide part structures or analogues. Owing
to the fast progress in oligosaccharide synthesis during the last years the synthesis of these
often most complex structures has become feasible. Syntheses of a number of complex
oligosaccharides corresponding to structures, both CPS and LPS, from the microbes
Haemophilus influenzae, Neisseria meningitidis, and Cryptococcus neoformans, including
synthetic challenges like seven and eight carbon sugars and various phosphate diester groups
(both as substituents and anomerically linked), will be presented, as well as their conjugation to
carrier proteins and evaluation as vaccine candidates.
Stefan Oscarson,
Centre for Synthesis and Chemical Biology, University College Dublin,
Belfield, Dublin 4, Ireland
