title: Pneumococcal conjugate vaccines.
abstract: We have prepared conjugates of pneumococcal type 4 polysaccharides (PS4) or oligosaccharides to tetanus toxoid using the carbodiimide method. The use of a spacer, 6-aminohexanoic acid, resulted in higher incorporation of carrier protein. Conjugates contained up to 10% free polysaccharide, but no free protein. In general, polysaccharide conjugates induced higher anti-PS4 IgG antibody titers than oligosaccharide conjugates. Conjugates with the highest amount of incorporated protein were the most immunogenic. The response to conjugated PS4 does show characteristics of a T cell-dependent antibody response, in terms of both isotype distribution and induction of immunological memory. Repeated immunization with high doses of PS4TT conjugate resulted in a virtually negative anti-PS4 IgG response, suggestive of the induction of high dose tolerance.
authors.affiliation: Department of Immunology, University Hospital for Children and Youth Het Wilhelmina Kinderziekenhuis, Utrecht, The Netherlands.
authors.forename: C C
authors.initials: CC
authors.lastname: Peeters
authors.forename: A M
authors.initials: AM
authors.lastname: Tenbergen-Meekes
authors.forename: B
authors.initials: B
authors.lastname: Haagmans
authors.forename: D
authors.initials: D
authors.lastname: Evenberg
authors.forename: J T
authors.initials: JT
authors.lastname: Poolman
authors.forename: B J
authors.initials: BJ
authors.lastname: Zegers
authors.forename: G T
authors.initials: GT
authors.lastname: Rijkers
mesh_terms: D000818:Animals; D002352:Carrier Proteins; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007122:Immunoelectrophoresis; D007074:Immunoglobulin G / Q000276:immunology; D051379:Mice; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013745:Tetanus Toxoid / Q000737:chemistry; D014614:Vaccines, Synthetic
chemical_list: D002352:Carrier Proteins; D007074:Immunoglobulin G; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; D014614:Vaccines, Synthetic