Type-Specific Inhibition of Preopsonization Versus Immunoprecipitation by Streptococcal M Proteins

AUTOR(ES)

Beachey, Edwin H.

RESUMO

Purified M protein of group A streptococci inhibits in vitro phagocytosis of bacteria nonspecifically when it is mixed directly with the test blood. We devised a method of preopsonization inhibition that avoids direct contact between the test blood and the opsonic inhibitory agent. Each of the M proteins tested by this method inhibited opsonization and phagocytosis of only homologous-type streptococci. Titration of the M antigen in various purified preparations demonstrated a clear dissociation between titers of type-specific precipitating M antigen and type-specific opsonic inhibitory M antigen. Since opsonization reflects protective antibody, assays of M protein based on reaction with opsonic antibody should reflect more accurately the presence of the type-specific M determinant involved in protective immunity against streptococcal infections.

Documentos Relacionados

• TYPE-SPECIFIC STREPTOCOCCAL IMMUNIZATION WITH ORAL VACCINE
• Type-Specific Opsonic Antibodies in Streptococcal Pyoderma
• Type-specific antibodies to structurally defined fragments of streptococcal M proteins in patients with acute rheumatic fever.
• Inhibition of leptospiral agglutination by the type-specific main antigens of leptospiras.
• Cell type-specific inhibition of p53-mediated apoptosis by mdm2.