Suppression of reaginic antibodies with modified allergens. II. Abrogation of reaginic antibodies with allergens conjugated to polyethylene glycol.

The two immunogenic preparations, ovalbumin (OA) and the nondialysable constituents of the aqueous extract of ragweed pollen (RAG), were conjugated with polyethylene glycols of molecular weights of 6,000 and 20,000 (PEG6 and PEG20) with the aid of cyanuric chloride. The i.v. administration of OA-PEG6 or OA-PEG20 into normal mice or into mice sensitized to a state of immediate hypersensitivity to dinitrophenylated OA (DNP3-OA) resulted, respectively, in the suppression of the primary or secondary IgE responses to DNP and OA. Similarly, the administration of RAG-PEG6 abrogated the primary as well as the ongoing anti-RAG reaginic responses in mice sensitized to RAG. The unresponsiveness of spleen cells from animals which had received a tolerogenic dose of OA-PEG6 was also maintained after transfer into X-irradiated (550 rad) mice. The suppressive effects of the tolerogenic PEG conjugates of OA and RAG were shown to be immunologically specific. It is, therefore, suggested that PEG-modified allergens may prove useful for the abrogation of the IgE response to a variety of allergens responsible for conditions of common hypersensitivity in man.