Common antigenic and allergenic determinants on codfish proteins detected with mouse monoclonal IgG and human IgE antibodies.

The antigenic and allergenic profiles of codfish extract have been examined and a comparison made of the specificities of the determinants defined by mouse monoclonal antibodies and human IgE antibodies. By gel electrophoresis, codfish extract was found to comprise a heterogeneous mixture of proteins, in which the principal component and allergen was Gad cI (allergen M). Using monoclonal antibodies and sera from human cod-allergic subjects as immunological probes, common antigenic and allergenic determinants were demonstrated on some codfish proteins. It was also established that, although two monoclonal antibodies recognized the same determinant on Gad cI, there was no cross-reactivity between this determinant and those specified by IgE antibodies in the sera of cod-allergic patients. The specificity of IgE populations directed against Gad cI was found to vary from patient to patient, and was indicative of the existence of two types of allergenic determinants: those unique to a particular allergen and those shared by other proteins in the extract. These studies promote speculation regarding the relative immunogenicity of antigenic and allergenic determinants and the size and diversity of the IgE repertoire, given the potential immunogenicity of the entire protein surface.