Specific Immunologic Unresponsiveness to Synthetic Polypeptide Antigens

Abstract
The injection of two synthetic polypeptide antigens into adult rabbits treated with 6-mercaptopurine, or into newborn rabbits, resulted in immunological "unresponsiveness" to subsequent immunizations with these antigens. The "tolerant" animals were shown to be reactive toward the non-related antigen ovalbumin.