Delayed Hypersensitivity to a Conjugate of Polytyrosine and its Inhibition by Haptens

RECENT investigations concerning the nature of the antigenic determinants involved in delayed hypersensitivity to hapten–protein conjugates have pointed to the important part played by the protein carrier 1,2 . In addition, some aspects of the heterogeneity of the response have been clarified 3 . In recent experiments reported by us 4 , guinea pigs were immunized with arsanilic acid (ars) coupled to guinea pig serum albumin. They reacted with the same hapten coupled to many unrelated proteins, suggesting a high degree of hapten-specificity. Positive reactions elicited by heterologous haptens coupled to guinea pig serum albumin were also noted and considered to be a response to antigenic determinants produced or revealed by the chemical process of conjugation with diazonium salts.