Hapten and carrier specificities of cellular and humoral responses to highly substituted dinitrophenyl-human gamma-globulins in guinea-pigs.

Delayed hypersensitivity (DH) and antibody reactions to the carrier and to the hapten have been studied in guinea-pigs immunized with different doses of highly substituted dinitrophenyl-human gamma-globulins (DNP56-HGG) in Freund's complete adjuvant (FCA). The results confirm that DH reactions are specific for the carrier while antibody-mediated reactions are specific for the hapten in the early stages of the immune response. Later in the response, however, DH reactions to the hapten as well as a transient humoral reaction to the carrier could be observed. T cells specific for the hapten and B cells specific for the carrier are therefore triggered after a single infection of a highly substituted hapten-carrier conjugate in FCA. Their regulatory functions in the immune response to hapten-carrier conjugates are discussed.