title: Non-immune Fab- and Fc- mediated interactions of avian Ig with S. aureus and group C and G streptococci.
abstract: Serum samples from 19 avian species representing 8 orders were tested for their capacity to inhibit the Fab- and Fc-mediated immunoglobulin binding to protein A-carrying S. aureus and protein G-carrying group C and G streptococci. Four species (mallard, dunlin, starling and blackbird) belonging to three different orders showed a high degree of Fc-mediated protein A- and protein G-reactivity. Five species demonstrated a high level and nine species exhibited a low level of Fab-mediated protein A-reactivity. The four species identified as Fc-reactive were capable of Fab-mediated immunoglobulin binding with streptococcal surface proteins but incapable of Fab-mediated protein A binding. SDS-PAGE analysis confirmed that the protein A-Sepharose affinity purified material contained proteins corresponding to immunoglobulin chains. Inhibition results by avian sera were confirmed by direct binding of protein A-reactive proteins to bacteria, by precipitation in gel and by Western blot analysis of binding to protein A and protein G, respectively.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology; D001717:Birds / Q000276:immunology*; D005779:Immunodiffusion; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007141:Immunoglobulin Fc Fragments / Q000276:immunology; D007136:Immunoglobulins / Q000276:immunology*; D007163:Immunosorbent Techniques; D011485:Protein Binding; D013205:Staphylococcal Protein A / Q000378:metabolism; D013211:Staphylococcus aureus / Q000276:immunology*; D013291:Streptococcus / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D007140:Immunoglobulin Fab Fragments; D007141:Immunoglobulin Fc Fragments; D007136:Immunoglobulins; D013205:Staphylococcal Protein A