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DIFFERENTIAL SUSCEPTIBILITY OF CELL‐BOUND STREPTOCOCCAL IMMUNOGLOBULIN Fc‐RECEPTORS TO AUTOLYTIC DEGRADATION
Author(s) -
SCHALÉN CLAËiS,
SVENSSON MAJLIS,
CHRISTENSEN POUL
Publication year - 1982
Publication title -
acta pathologica microbiologica scandinavica series b: microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0108-0180
DOI - 10.1111/j.1699-0463.1982.tb00130.x
Subject(s) - receptor , incubation , microbiology and biotechnology , antibody , iodoacetic acid , chemistry , immunoglobulin g , streptococcus , strain (injury) , fc receptor , streptococcaceae , biochemistry , biology , bacteria , immunology , enzyme , anatomy , genetics , antibiotics
The susceptibility of IgA and IgG Fc‐receptors of different streptococci to autolytic degradation was tested by incubating washed bacteria in phosphate‐buffered saline at 37°C for 24‐72 h. Before incubation, strain Ml bound 74 per cent of 2.5 μg radio‐labelled IgG added to 200 μl of the suspension, and strain M4 bound 85 per cent of 2.5 μg radio‐labelled IgA; both types of binding decreased to less than 15 per cent. Evidence was obtained that the decrease in binding was caused by digestion of the respective receptors, and not by degradation of the immunoglobulins or through inhibition by solubilized Fc‐receptors. The autolytic process was inhibited by EDTA, iodoacetic acid, benzamidinium chloride, phenylmethylsulfonyl fluoride and diisopropylfluorophosphate. The IgG Fc‐receptors in other types of group A streptococci (including type M4) and a group C and a group G strain were not affected by such prolonged incubation, also when strains were mixed with M‐type 1 streptococci from the start of incubation. These findings, which thus revealed certain differences in stability between streptococcal Fc‐receptors, are discussed in relation to the intracellular degradation of streptococci.