title: Antibodies against pneumococcal C-polysaccharide are not protective.
abstract: The ability of antibodies against C-polysaccharide (C-Ps) to protect against experimental pneumococcal infection was examined in a mouse model. No protection against types 6A and 14 pneumococcal infection could be demonstrated neither with mouse monoclonal antibodies against C-Ps, specific for phosphorylcholine (PC) or for C-Ps backbone, nor for polyclonal rabbit immunsera against C-Ps. The monoclonal antibody with PC-specificity was protective against infection with type 27 pneumococcus, that has PC as part of its capsular polysaccharide. Type-specific mono- and polyclonal antibodies were highly protective against infection with the homologous type. We conclude that no species-specific protection can be achieved against intraperitoneal Streptococcus pneumoniae infection with optimally capsulated bacteria in outbred mice by passive immunization with antibodies to C-Ps.
authors.affiliation: World Health Organization Collaborating Centre for Reference and Research on Pneumococci, Statens Seruminstitut, Copenhagen, Denmark.
authors.forename: S V
authors.initials: SV
authors.lastname: Nielsen
authors.forename: U B
authors.initials: UB
authors.lastname: Sørensen
authors.forename: J
authors.initials: J
authors.lastname: Henrichsen
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D011008:Pneumococcal Infections / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000472:pathogenicity; D014774:Virulence
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D011135:Polysaccharides, Bacterial; C027158:polysaccharide C-substance (Streptococcus)