[Detection and determination of the biological activity of IgG Fc receptors in strains of streptococci isolated from carriers and patients].

Mechanism of anti-IgG induction during the immunization of animals by IgG Fc+ streptococcal strains has been studied. Streptococcal proteolytic activity did not influence microbial IgG Fc-receptor ability to induce synthesis of anti-IgG. The induction of anti-IgG by purified Fc-receptors and rabbit IgG, eluted from streptococcal IgG Fc-receptors has been examined. Biological activity of streptococcal IgG Fc+ strains, isolated from carriers and patients with acute streptococcal diseases has been evaluated according to their ability to induce synthesis of anti-IgG; data on the distribution of IgG Fc+ and IgG Fc- streptococcal strains among carriers and patients with streptococcal diseases are presented. IgG Fc+ strains were mostly isolated from patients with streptococcal diseases. Mechanisms of the transformation of rabbit IgG into autoantigen are discussed.