Effect of the Carrier Protein on Idiotypic Specificities of Antihapten Antibodies Produced in an Inbred Strain of Mice

Abstract

Abstract Antihapten antibodies formed in A/J mice in response to keyhole limpet hemocyanin (KLH)-p-azophenylarsonate (KLH-Ar) show strong intrastrain idiotypic cross-reactions. These antibodies also share idiotypic specificities with antihapten antibodies produced in response to the same hapten coupled to a different carrier, bovine γ-globulin (BGG). Nearly all specificities present in the antihapten antibody population elicited by KLH-Ar were also found in the anti-BGG-Ar antibodies of most mice, as shown by the capacity of the latter antibody populations to displace most of the labeled immunogen from its antiidiotypic antibodies. On the average, however, significantly larger amounts of anti-BGG-Ar, as compared to anti-KLH-Ar antibodies, were required for inhibition. This demonstrates that populations lacking the cross-reacting idiotype were also stimulated by BGG-Ar. The results indicate that many receptors on lymphocytes that are capable of being stimulated by KLH-Ar can also interact effectively with BGG-Ar. The fact that idiotypic specificity is relatively independent of the carrier protein suggests that it is determined at the level of the bone marrow-derived cell.