Characterization of the domain of fibronectin-binding protein I of Streptococcus pyogenes responsible for elicitation of a protective immune response.
- Citation data:
Infection and immunity, ISSN: 0019-9567, Vol: 69, Issue: 1, Page: 622-5
- Publication Year:
- Repository URL:
- PMC97932; 97932
- Immunology and Microbiology; Medicine; immune; fibronectin; domain; protective; elicitation; responsible; pyogenes; streptococcus; i; protein; response; binding; characterization; Medicine and Health Sciences; Social and Behavioral Sciences
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.