Tolerizing effect of DNP-ficoll on IgE antibody production.

A/J and DBA/1 mice were infected with 750 third-stage larvae of Nippostrongylus brasiliensis and immunized with 1 mug dinitrophenylated N. brasiliensis extract (DNP-Nb) with 1 mg Al(OH)3 to produce high titers of anti-hapten IgG1 and IgE antibody. Partial tolerance to the production of anti-hapten IgG1 and IgE antibody could be induced by DNP-Ficoll from 5 weeks before to 1 week after the DNP-Nb immunization. The tolerized state persisted through the duration of the experiments. However, no tolerizing effect could be demonstrated on secondary antihapten IgE antibody production induced by DNP-Nb. Moreover, DNP-Ficoll failed to evoke anti-hapten IgG1 or IgE antibody production.