title: Identification of B- and T-cell epitopes of BB, a carrier protein derived from the G protein of Streptococcus strain G148.
abstract: Most conventional vaccines consist of killed organisms or purified antigenic proteins. Such molecules are generally poorly immunogenic and need to be coupled to carrier proteins. We have identified a new carrier molecule, BB, derived from the G protein of Streptococcus strain G148. We show that BB is able to induce strong antibody responses when conjugated to peptides or polysaccharides. In order to localize T and B cell epitopes in BB and match them with the albumin-binding region of the molecule, we immunized mice with BB, performed B and T pepscan analyses, and compared the results with pepscan done with sera and cells from humans. Our results indicate that BB has two distinct T helper epitopes, seven linear B-cell epitopes, and one conformational B-cell epitope in BALB/c mice. Four linear B-cell epitopes were identified from human sera, three of which overlapped mouse B-cell epitopes. Finally, three human T-cell epitopes were detected on the BB protein. One of these T-cell epitopes is common to BALB/c mice and humans and was localized in the region that contains the albumin-binding site. These data are of interest for the optimization of new carrier molecules derived from BB.
authors.affiliation: Centre d'Immunologie Pierre Fabre, 74164 Saint-Julien en Genevois, France.
authors.forename: Liliane
authors.initials: L
authors.lastname: Goetsch
authors.forename: Jean Francois
authors.initials: JF
authors.lastname: Haeuw
authors.forename: Thierry
authors.initials: T
authors.lastname: Champion
authors.forename: Christine
authors.initials: C
authors.lastname: Lacheny
authors.forename: Thien
authors.initials: T
authors.lastname: N'Guyen
authors.forename: Alain
authors.initials: A
authors.lastname: Beck
authors.forename: Nathalie
authors.initials: N
authors.lastname: Corvaia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000276:immunology*; D002352:Carrier Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry* / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry* / Q000276:immunology; D006801:Humans; D007114:Immunization; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D011134:Polysaccharides / Q000737:chemistry / Q000276:immunology; D014764:Viral Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D018985:Epitopes, B-Lymphocyte; D018984:Epitopes, T-Lymphocyte; C034284:IgG Fc-binding protein, Streptococcus; D010455:Peptides; D011134:Polysaccharides; D014764:Viral Proteins