METHODS: Plant-based transient expression of the fusion of a synthetic non-immunogenic carrier with an allergen component was used to develop allergen bearing bioparticles as a new vector for allergen specific immunotherapy. Bioparticles harboring spikes of oligomerized major dust mite allergen are used here for illustration. These bioparticles were purified, characterized and used for a head-to-head mouse immunogenicity and allergenicity study in comparison with the same allergen in a soluble form and whole dust mite commercial extracts. The ability of these bioparticles to induce degranulation of human basophils derived from house dust mite allergic individuals was also studied.
RESULTS: In a continuum of pre-clinical studies, two injections of allergen-bearing bioparticles were shown to induce a powerful IgG2a immunogenic response and yet without a significant impact on bronchial resistance in a murine model. Strikingly, allergen bearing bioparticles did not induce degranulation of basophils derived from human volunteers allergic to the allergen.
CONCLUSIONS: Our current results suggest that plant-made allergen-bearing bioparticles, by virtue of their high immunogenicity and low allergenicity have the potential to substantially improve the safety and efficacy of future allergy therapeutics.