The gut as target organ for oral immunovaccination with allergen DNA: new hope for patients with anaphylactic reactions to food?

Food allergy is a common and often fatal disease with no eVective treatment. We describe here a new immunoprophylactic strategy using oral allergen-gene immunization to modulate peanut antigen-induced murine anaphylactic responses. Oral administration of DNA nanoparticles synthesized by complexing plasmid DNA with chitosan, a natural biocompatible polysaccharide, resulted in transduced gene expression in the intestinal epithelium. Mice receiving nanoparticles containing a dominant peanut allergen gene (pCMVArah2) produced secretory IgA and serum IgG2a. Compared with non-immunized mice or mice treated with ‘naked’ DNA, mice immunized with nanoparticles showed a substantial reduction in allergen-induced anaphylaxis associated with reduced levels of IgE, plasma histamine and vascular leakage. These results demonstrate that oral allergen-gene immunization with chitosan–DNA nanoparticles is eVective in modulating murine anaphylactic responses, and indicate its prophylactic utility in treating food allergy. Gut 1999;45:11–12 11 group.bmj.com on October 21, 2017 Published by http://gut.bmj.com/ Downloaded from