title: Location of variable and conserved epitopes among the multiple serotypes of streptococcal M protein.
abstract: In studies primarily confined to the amino-terminal region of the fibrillar group A streptococcal M protein, only limited immunological crossreactions have been observed among M serotypes. In this investigation, two monoclonal antibodies generated against nearly the entire M6 molecule (LysM6) were used to determine the extent of crossreactions among M serotyping strains and to localize their epitopes on the M molecule. Colony blot and immunoblot analyses revealed that an epitope responsible for crossreactions among 5 of the 56 strains of different M serotypes tested is located in the amino-terminal half of the molecule, distal to the cell surface. In contrast, a more common crossreactive epitope, reacting with 20 of the 56 strains, is located near the middle of the M molecule. These studies also reveal that the more conserved determinant, located more proximally to the cell surface, is accessible to the immune system, even on the whole organism, and, thus, may be useful in devising means to protect against infections by multiple group A streptococcal M serotypes.
authors.forename: K F
authors.initials: KF
authors.lastname: Jones
authors.forename: B N
authors.initials: BN
authors.lastname: Manjula
authors.forename: K H
authors.initials: KH
authors.lastname: Johnston
authors.forename: S K
authors.initials: SK
authors.lastname: Hollingshead
authors.forename: J R
authors.initials: JR
authors.lastname: Scott
authors.forename: V A
authors.initials: VA
authors.lastname: Fischetti
mesh_terms: D000907:Antibodies, Bacterial / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000276:immunology; D000942:Antigens, Bacterial / Q000032:analysis / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000032:analysis / Q000276:immunology*; D001666:Binding Sites, Antibody; D002352:Carrier Proteins; D003429:Cross Reactions; D000939:Epitopes / Q000032:analysis / Q000276:immunology*; D012703:Serotyping; D013297:Streptococcus pyogenes / Q000145:classification / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D000939:Epitopes; C014689:streptococcal M protein