Effects of tolerogenic conjugates in a canine model for reaginic hypersensitivity. I. suppression of hapten-specific IgE antibody response.

Intraperitoneal administration to dogs of conjugates consisting of the 2,4-dinitrophenyl (DNP) groups coupled to nonimmunogenic macromolecules such as the copolymer of D-glutamic acid and D-lysine (DNP16-DGL) prior to sensitization with DNP2-ovalbumin led to the development of hapten-specific tolerance with respect to the IgE antibody response. Administration of these same conjugates to sensitized dogs resulted in complete abrogation of the ongoing anti-DNP IgE antibody production. A similar hapten-specific suppression of the ongoing anti-DNP response was also observed using the conjugates of DNP9-canine gamma globulins, and the tolerogenic effect was dose-dependent. The state of hapten-specific immunosuppression induced by these two types of tolerogenic conjugates was maintained despite repeated booster injections of the sensitizing antigens at biweekly inervals.