Mimotope and anti-idiotypic vaccines to induce an anti-IgE response

We have defined epitopes on human IgE by screening different phage display random peptide libraries with a monoclonal anti-IgE antibody termed BSW17, The selected mimotopes and epitopes within the C epsilon 3 and C epsilon 4 region of IgE induced antibodies that were nonanaphylactogenic and had biol ogical activity similar to BSW17. The chemically synthesized and KLH-couple d IgE epitopes or mimotopes were used to induce an anti-IgE response in rhe sus monkeys. The immunized rhesus monkeys were subsequently protected in a PCA test when sensitized with human IgE and triggered with the correspondin g allergen. Furthermore, using the same monoclonal anti-IgE antibody, we al so generated an anti-idiotypic antibody that showed sequence homology with the IgE epitope in the C epsilon 3 domain. This anti-idiotypic antibody as well as the mimotopes were then used in a mouse model to induce orally an a nti-IgE immune response. For this purpose mice were fed by intragastric gav ages with bacteriophages displaying the small IgE-homologous structures. Or ally immunized mice produced serum anti-IgE antibodies that were inhibited by BSW17 suggesting that it may be possible to induce a systemic anti-IgE r esponse orally.