Pneumococcal capsular polysaccharides

Glucuronic acid is also constituent of pathogenic bacteria. The simplest structure for a pneumococcal capsular polysaccharide has the repeating unit [- 4)-/3-d-G1c-(1 3)-/3-D-GlcpA-(l ]ra.120... 

Porro M, Costantino P, Viti S, Vannozzi F, Naggi A, Torri G. 41. Specific antibodies to diphtheria toxin and type 6A pneumococcal capsular polysaccharide induced by a model of semi-synthetic glycoconjugate antigen. Mol. Immunol. 1985 22 907-919. 

Prevnar is a glycoconjugate heptavalent pneumococcal vaccine for young children made from the polysaccharide capsule of the pneumococcus (20). Although older vaccines made from pneumococcus capsular polysaccharide are available for adults, young children cannot make antibodies to the capsule. By coupling the pneumococcal capsular polysaccharide with a protein carrier, a vaccine was created that will trigger an infant s immune system to produce antibodies. 

When high molecular weight pneumococcal capsular polysaccharide is injected intraperitoneally into rats, the antigen is excreted in the urine. Examination of the molecular weight profile of the excreted product indicates that significant degradation has taken place. 

Pneumococcal capsular polysaccharide vaccine was shown to be effective at preventing pneumococcal pneumonia in young American military recruits (47) and in otherwise healthy South African gold miners (44,46). However, it is not clear whether data from these trials can be generalized to nonepidemic situations in the United States, where most pneumococcal disease in adults occurs in the elderly or in persons with chronic medical conditions. Vaccine... 

Robbins JB, Austrian R, Lee CJ, et al. Considerations for formulating the second-generation pneumococcal capsular polysaccharide vaccine with emphasis on the cross-reactive types within groups. J Infect Dis 1983 148 1136-1159. 

Not all of the pneumococcal capsular polysaccharides have had their structures completely determined. Because of their antigenicity and use in producing vaccines, there has been great interest in this field of carbohydrate chemistry. We will consider only the structures of six types of 5. pneumoniae capsular polysaccharides that have had their structures definitively determined. 

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