| Abstract: | The use of the gel precipitation test showed that adsorption of preparations of human IgG, the Fc fragments isolated from them, and of preparations of rabbit IgG with cultures of group A streptococcus inhibits the reaction of these preparations with antiglobulin sera. No inhibition of reactions of F(ab')2 fragments took place as a result of their adsorption by the same cultures. The results confirm that certain strains of group A streptoccocus contain immunoglobulin receptors (Ig receptors), capable of reacting with Fc sites of human and rabbit IgG. The Ig receptors were shown to be destroyed by pepsin. No Ig receptors could be found by the use of this method in hydrochloric acid extracts obtained from streptococci containing these receptors. The method used in the investigation is suitable for detecting the presence of Ig receptors in streptococcal cultures.Laboratory of Streptococcal Infections, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 9, pp. 319–322, September, 1979. |
