title: Group A Streptococcus produce pilus-like structures containing protective antigens and Lancefield T antigens.
abstract: Although pili have long been recognized in Gram-negative pathogens as important virulence factors involved in adhesion and invasion, very little is known about extended surface organelles in Gram-positive pathogens. Here we report that Group A Streptococcus (GAS), a Gram-positive human-specific pathogen that causes pharyngitis, impetigo, invasive disease, necrotizing fasciitis, and autoimmune sequelae has long, surface-exposed, pilus-like structures composed of members of a family of extracellular matrix-binding proteins. We describe four variant pili and show that each is recognized by a specific serum of the Lancefield T-typing system, which has been used for over five decades to characterize GAS isolates. Furthermore, we show that immunization of mice with a combination of recombinant pilus proteins confers protection against mucosal challenge with virulent GAS bacteria. The data indicate that induction of a protective immune response against these structures may be a useful strategy for development of a vaccine against disease caused by GAS infection.
authors.affiliation: Chiron Vaccines, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Marirosa
authors.initials: M
authors.lastname: Mora
authors.forename: Giuliano
authors.initials: G
authors.lastname: Bensi
authors.forename: Sabrina
authors.initials: S
authors.lastname: Capo
authors.forename: Fabiana
authors.initials: F
authors.lastname: Falugi
authors.forename: Chiara
authors.initials: C
authors.lastname: Zingaretti
authors.forename: Andrea G O
authors.initials: AG
authors.lastname: Manetti
authors.forename: Tiziana
authors.initials: T
authors.lastname: Maggi
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Taddei
authors.forename: Guido
authors.initials: G
authors.lastname: Grandi
authors.forename: John L
authors.initials: JL
authors.lastname: Telford
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis*; D001483:Base Sequence; D005260:Female; D036781:Fimbriae Proteins / Q000276:immunology; D010861:Fimbriae, Bacterial / Q000502:physiology*; D007114:Immunization; D051379:Mice; D008969:Molecular Sequence Data; D013290:Streptococcal Infections / Q000517:prevention & control; D013297:Streptococcus pyogenes / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D037521:Virulence Factors / Q000032:analysis
chemical_list: D000942:Antigens, Bacterial; D037521:Virulence Factors; D036781:Fimbriae Proteins