A radioimmunoassay for serum and gingival crevicular fluid antibodies to a purified protein of Streptococcus mutans.
A solid-phase radioimmunoassay was developed to measure serum IgG antibodies to a purified protein antigen I/II prepared from Streptococcus mutans. The assay was specific to this antigen and significant binding of 125I-radiolabelled antiserum was found only in sera from rhesus monkeys immunized with the antigen I/II but not in sham-immunized monkeys or those immunized with streptococcal antigen III. A very significant correlation was found in serum IgG antibodies tested by the radioimmunoassay and an immunofluorescent technique (r = 0.88, P less than 0.001). The sensitivity of the double-layer radioimmunoassay was increased 10 times by the addition of a third antibody layer and this enabled gingival crevicular fluid antibodies to be measured. Comparison of paired samples of serum and crevicular fluid revealed a very significant correlation between IgG antibodies to streptococcal antigen I/II in the the two fluids (P less than 0.001). These findings suggest that serum antibodies can reach the tooth surface via gingival crevicular fluid.
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D000918:Antibody Specificity; D001426:Bacterial Proteins / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D005883:Gingival Crevicular Fluid / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008253:Macaca mulatta; D011863:Radioimmunoassay / Q000379:methods*; D013295:Streptococcus mutans / Q000276:immunology*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G