Concentration of Cross-Reacting Idiotypic Specificities in Unrelated Mouse Immunoglobulins

Abstract

Abstract Myeloma proteins and populations of antibody molecules from individual donors possess unique antigenic (idiotypic) determinants (1–3). Gell and Kelus (4) first proposed that a given idiotypic specificity is characteristic of a clone of cells, i.e., of cells descended from a common precursor. It has been suggested, however, that certain idiotypic specificities might actually reflect the presence of unique antigenic determinants in certain subgroups of polypeptide chains, selected by the antigen (5). If this were the case nonspecific immunoglobulin populations would be expected to exhibit various idiotypic specificities in low concentrations. The present experiments define upper limits for the concentrations of idiotypic specificities of mouse antihapten antibodies in normal IgG and in mouse antibodies of unrelated specificity. The antibodies used to elicit antiidiotypic (anti-D)2 antibodies were prepared in strain A/J mice by immunization with keyhole limpet hemocyanin (KLH)-p-azophenylarsonate or KLH-p-azobenzoate (6). Anti-D antibodies directed to the antihapten antibodies were prepared and were quantified by an indirect precipitation method, as described elsewhere (6).