Reaginic antibody formation in the mouse. VI. Suppression of IgE and IgG antibody responses to ovalbumin following the administration of high dose urea-denatured antigen.

The major antigenic determinants in ovalbumin molecules (OA) were lost following denaturation in 8 M urea. The urea-denatured antigen (UD-OA) failed to combine with anti-OA antibody, but was capable of priming mouse T cells specific for OA. BDF₁ mice primed with alum-precipitated OA were given three intravenous injections of 100 μg UD-OA at 3, 5, and 7 days after the primary immunization. The treatment with UD-OA suppressed both IgE and IgG antibody responses to OA. The same treatment of OA-primed animals with intravenous injections of OA resulted in suppression of IgE antibody response but enhanced IgG antibody response. Intravenous injections of either OA or UD-OA suppressed both IgE and IgG anti-DNP antibody responses of DNP-OA-primed animals but failed to suppress anti-hapten antibody responses to DNP-keyhole limpet hemocyanin. The effect of the treatment on helper T cells and B memory cells in OA-primed animals was studied by adoptive transfer experiments. The results showed that the OA-treatment as well as UD-OA-treatment suppressed the development of both helper function of T cells and B memory cells in the spleen, but the UD-OA treatment was more effective than OA-treatment for the suppression of B cell development. Possible mechanisms for the suppression of the development of immunocompetent cells were discussed.     

Immunochemical studies of dextran coupled ragweed pollen allergen, antigen E.

The major allergen of ragweed pollen antigen E has been coupled to periodate oxidized dextrans, followed with sodium borohydride reduction to stabilize the linkages. Two products having molecular weights of about 100,000 and 140,000 were prepared, and the molar ratio of dextran to antigen E in both products was the same in the range of 2–5. The antigenic and the allergenic activities of the products were on a molar basis about seven to eight fold less than those of antigen E. On dextranase digestion of the products, their biological activities were restored. The products were immunogenic in rabbits to stimulate the formation of antibodies reacting with antigen E and with dextran.