Identification of B- and T-cell epitopes of BB, a carrier protein derived from the G protein of Streptococcus strain G148.
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.
Goetsch
Liliane
L
Centre d'Immunologie Pierre Fabre, 74164 Saint-Julien en Genevois, France.
Haeuw
Jean Francois
JF
Champion
Thierry
T
Lacheny
Christine
C
N'Guyen
Thien
T
Beck
Alain
A
Corvaia
Nathalie
N
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
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