Characterization of the domain of fibronectin-binding protein I of Streptococcus pyogenes responsible for elicitation of a protective immune response.
Fibronectin-binding protein I (SfbI) represents a major adhesin of Streptococcus pyogenes. Mice were intranasally immunized with recombinant proteins spanning different portions of SfbI to identify the minimal fragment able to elicit a protective response against a lethal challenge with S. pyogenes. The strongest cellular responses and the highest levels of antigen-specific secretory immunoglobulin A (IgA) were detected in mice immunized with the fibronectin-binding region of SfbI. In contrast, animals vaccinated with a polypeptide spanning the aromatic and proline-rich regions showed the highest titers and fastest IgG response in serum. Vaccination with either SfbI without a membrane anchor and signal peptide or a polypeptide encompassing its fibronectin-binding regions resulted in efficient protection against heterologous challenge (60% and 80%, respectively), whereas the use of a polypeptide lacking this region conferred marginal protection (10%) with respect to the control group (0%). These results demonstrate that the fibronectin-binding region of SfbI is a promising candidate antigen for developing anti-S. pyogenes vaccines.
Schulze
K
K
Department of Microbial Pathogenesis and Vaccine Research, Division of Microbiology, GBF-German Research Centre for Biotechnology, D-38124 Braunschweig, Germany.
Medina
E
E
Talay
S R
SR
Towers
R J
RJ
Chhatwal
G S
GS
Guzmán
C A
CA
D018829:Adhesins, Bacterial; D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D001665:Binding Sites; D002352:Carrier Proteins / Q000276:immunology*; D005399:Fishes; D007114:Immunization; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D051379:Mice; D013297:Streptococcus pyogenes / Q000276:immunology*
D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; C078635:fibronectin-binding proteins, bacterial