title: Humoral immunity to dietary antigens in healthy adults. Occurrence, isotype and IgG subclass distribution of serum antibodies to protein antigens.
abstract: The occurrence of antibodies to five dietary protein antigens in the sera from 21 healthy adults was investigated by a modified Farr assay. Antibody to ovalbumin (OA) occurred most frequently (90%) whereas only 24% had antibodies to alpha-lactalbumin (ALA). No correlation was noted between the titer of antibodies against bovine serum albumin (BSA) and OA in the single individual. The avidity constants (10(8)-10(9) l/mol) and cross-reactivities against other albumins of anti-BSA antibodies in two human sera were comparable to that of the antibodies in pooled hyperimmune rabbit antiserum. Crossed radioimmunoelectrophoresis showed serum anti-BSA and anti-OA antibodies to be predominantly of the IgG class (13/13, 10/10), occasionally of the IgA- (6/13, 1/10) and rarely of the IgM class (1/13, 0/10). Analysis by radioelectroimmunoassay (rocket immunoelectrophoresis) of the IgG subclass distribution of anti-BSA and anti-OA antibodies showed total absence of IgG3. In contrast, antibodies of the IgG4 subclass were frequently present even in sera with very low levels of total IgG4.
mesh_terms: D000328:Adult; D000915:Antibody Affinity; D000941:Antigens / Q000276:immunology*; D003429:Cross Reactions; D004044:Dietary Proteins / Q000009:adverse effects*; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D007126:Immunoglobulin Allotypes / Q000276:immunology; D007074:Immunoglobulin G / Q000145:classification / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010047:Ovalbumin / Q000276:immunology; D012710:Serum Albumin, Bovine / Q000276:immunology
chemical_list: D000941:Antigens; D004044:Dietary Proteins; D007126:Immunoglobulin Allotypes; D007074:Immunoglobulin G; D012710:Serum Albumin, Bovine; D010047:Ovalbumin