title: Induction of immune response to Streptococcus pneumoniae by administration of oral viridans streptococci via phosphorylcholine determinant.
abstract: Expression of the phosphorylcholine (PC) epitope was examined in 48 viridans streptococcal strains, including Streptococcus pneumoniae R36a as the positive control, and their immunogenicity to induce an S. pneumoniae-cross-reactive response was evaluated in mice. Thirteen strains were found to express the PC epitope, while no obvious association was found between the taxonomic categories and PC expression. Serum antibody responses to S. pneumoniae cells were induced in mice by intraperitoneal injection of the PC-positive, but not PC-negative, strains. The cross-reactive antibodies induced by non-pneumococcal oral streptococci were readily inhibited by free hapten PC. IgM was the sole isotype of the anti-pneumococcal and anti-PC antibodies, and the phenomenon of immunological memory was not observed. Since the anti-PC antibody is critically important for resistance against pneumococcal infection in mice, the present results indicate the possibility that PC-expressing oral commensal bacteria have a significant influence on the hosts' responsiveness to S. pneumoniae.
authors.affiliation: Department of Preventive Dentistry, Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Miwa
authors.forename: Hiro-O
authors.initials: HO
authors.lastname: Ito
authors.forename: Masakazu
authors.initials: M
authors.lastname: Inoue
authors.forename: Takahiko
authors.initials: T
authors.lastname: Oho
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D003429:Cross Reactions; D000939:Epitopes; D005260:Female; D006801:Humans; D007132:Immunoglobulin Isotypes / Q000096:biosynthesis / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D009055:Mouth / Q000382:microbiology; D010767:Phosphorylcholine / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000276:immunology*; D034363:Viridans Streptococci / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000907:Antibodies, Bacterial; D000939:Epitopes; D007132:Immunoglobulin Isotypes; D010767:Phosphorylcholine