Food allergy is a common and often fatal disease with no effective 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 effective in modulating
murine anaphylactic responses, and indicate its prophylactic utility in treating
food allergy.
