a b s t r a c t
IgE-mediated allergy to chicken egg affects a large number of children and adults worldwide. The current
management strategy for egg allergy is strict avoidance, however this is impractical due to the presence
of eggs in a range of foods and pharmaceutical products including vaccines. Strict avoidance also poses
nutritional disadvantages due to high nutritional value of eggs. Allergen specific immunotherapy is being
pursued as a curative treatment, in which an allergic individual is gradually exposed to the allergen
to induce tolerance. Use of recombinant proteins for immunotherapy has been beneficial due to the
purity of the recombinant proteins compared to natural proteins. In this study, we produced IgE reactive
recombinant egg white proteins that can be used for future immunotherapy. Using E. coli as an expression
system, we successfully produced recombinant versions of Gal d 1, 2 and 3, that were IgE reactive when
tested against a pool of egg allergic patients’ sera. The IgE reactivity indicates that these recombinant
proteins are capable of eliciting animmune response,thus being potential candidates for immunotherapy.
We have, for the first time, attempted to produce recombinant versions of all 4 major egg white allergens
in E. coli, and successfully produced 3, with only Gal d 4 showing loss of IgE reactivity in the recombinant
version. The results suggest that egg allergy in Australian populations may mainly be due to IgE reactivity
to Gal d 3 and 4, while Gal d 1 shows higher IgE reactivity. This is the first report of a collective and
comparative immunological analysis of all 4 egg white allergens. The significance of this study is the
potential use of the IgE reactive recombinant egg white proteins in immunotherapy to treat egg allergic
patients.