A polyfunctional molecule produced by the conjugation of a synthetic polyion-immunostimulant with specific antigen and an inhibitor of mast cell activation: effects on histamine release

Polyfunctional molecules were prepared by appropriate conjugation of three moities (1) a polyion-immunostimulant (copolymer of N-vinylpyrrolidone with vinylamine-VP/VA), (2) an inhibitor of mediator secretion from mast cells (diphenylquinone-DPQ) and (3) a specific allergen (ovalbumin-OV). The conjugate of VP/VA with DPQ dose-dependently inhibited histamine release from rat and mouse mast cells induced by the selective releasing agents compound 48/80, ionophore A23187 and specific allergen. The DPQ bound to the polyion was responsible for the inhibitory action of the conjugate. OV conjugated with VP/VA/DPQ (VP/VA/DPQ-OV) was a weaker histamine releaser than OV alone. An immunoenzymatic assay showed that the reduction of the histamine releasing activity of OV in the conjugate was not connected with an inhibition of the antibody binding activity of the OV. The data here presented demonstrate the possibility of creating a polyfunctional molecule (for e.g. hyposensitization) with a decreased ability to induce allergic reactions by inserting a functional group which inhibits histamine secretion into the molecule.