title: Production and immunological analysis of IgE reactive recombinant egg white allergens expressed in Escherichia coli.
abstract: 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 an immune 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.
authors: NeuroAllergy Research Laboratory (NARL), School of Life and Environmental Sciences, Faculty of Science, Engineering and Built Environment, Deakin University, 75 Pigdons Road, Geelong 3216 VIC, Australia; Australian Animal Health Laboratory (AAHL), Biosecurity Flagship, Commonwealth Scientific and Industrial Research Organisation (CSIRO) , 5 Portarlington Road, East Geelong 3219 VIC, Australia; Poultry CRC, PO Box U242, University of New England, Armidale 2351 NSW, Australia.
authors: Pathum
authors: P
authors: Dhanapala
authors: Australian Animal Health Laboratory (AAHL), Biosecurity Flagship, Commonwealth Scientific and Industrial Research Organisation (CSIRO) , 5 Portarlington Road, East Geelong 3219 VIC, Australia; Poultry CRC, PO Box U242, University of New England, Armidale 2351 NSW, Australia.
authors: Tim
authors: T
authors: Doran
authors: Department of Allergy and Immunology, Royal Children's Hospital, 50 Flemington Road, Parkville 3052 VIC, Australia; Allergy and Immune Disorders, Murdoch Children's Research Institute, Melbourne Australia; The University of Melbourne, Australia.
authors: Mimi L K
authors: ML
authors: Tang
authors: NeuroAllergy Research Laboratory (NARL), School of Life and Environmental Sciences, Faculty of Science, Engineering and Built Environment, Deakin University, 75 Pigdons Road, Geelong 3216 VIC, Australia; Poultry CRC, PO Box U242, University of New England, Armidale 2351 NSW, Australia. Electronic address: cenk.suphioglu@deakin.edu.au.
authors: Cenk
authors: C
authors: Suphioglu
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D002645:Chickens; D003001:Cloning, Molecular; D003207:Conalbumin / Q000235:genetics / Q000276:immunology; D021181:Egg Hypersensitivity / Q000628:therapy*; D004527:Egg Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007108:Immune Tolerance; D007073:Immunoglobulin E / Q000276:immunology*; D007167:Immunotherapy / Q000379:methods*; D009113:Muramidase / Q000235:genetics / Q000276:immunology; D010047:Ovalbumin / Q000235:genetics / Q000276:immunology; D010059:Ovomucin / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000627:therapeutic use*
chemical_list: D000485:Allergens; D004527:Egg Proteins; D011994:Recombinant Proteins; D003207:Conalbumin; D010059:Ovomucin; D007073:Immunoglobulin E; D010047:Ovalbumin; D009113:Muramidase
keywords: Allergens; Egg allergy; Immunotherapy; Recombinant proteins