Anti-Bovine Serum Albumin Specificity and Binding Affinity after Termination of Tolerance to Bovine Serum Albumin

Abstract

Summary Rabbits tolerant to bovine serum albumin (BSA) were injected with soluble arsanil-sulfanil-BSA (A-S-BSA) to terminate the tolerant state. Following termination of the tolerant state the specificity of the antibodies produced as a result of periodic injections of soluble BSA was then assayed by antigen binding, inhibition and dissociation studies. By these criteria, antibody specificity and binding affinity immediately after the termination of tolerance were much higher for A-S-BSA than for BSA. After six monthly injections of BSA the binding affinity of the antibody for A-S-BSA was still appreciably higher than that for BSA when compared to normal rabbits injected in the same manner. However, antigen binding and inhibition studies showed that three of five previously tolerant animals were producing antibodies of approximately the same specificity for BSA as were the normal control animals. Normal control rabbits injected first with soluble A-S-BSA and then periodically with soluble BSA continued to produce antibodies with a higher specificity for A-S-BSA than for BSA for several months, although eventually the specificities for the two antigens became nearly equal. Based on lack of inactivation by mercaptoethanol, the antibody response at various times after the termination of tolerance does not have a significant 19 S component.