title: Protein A-like activity and streptococcal cross-reactions.
abstract: Recognition of the protein A-like activity of some strains of group A streptococci has thrown doubt on much previous work suggesting antigenic cross-reactions between these streptococci and mammalian tissues. The strains used in our previous studies have now been examined by the mixed reverse passive antiglobulin reaction (MRPAH) for the 'non-specific' absorption of purified Fc portion of human IgG. They were found to have only traces of activity. The strain of Staphylococcus aureus used to control 'non-specific' absorption by bacterial cell walls was strongly positive. Protein A-like material as detected in this way was not therefore responsible for our earlier results.
mesh_terms: D003429:Cross Reactions; D006386:Hemagglutination Tests; D007141:Immunoglobulin Fc Fragments / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D013205:Staphylococcal Protein A / Q000276:immunology*; D013211:Staphylococcus aureus / Q000276:immunology; D013297:Streptococcus pyogenes / Q000276:immunology*
chemical_list: D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A