Rapid production of recombinant allergens in Nicotiana benthamiana and their impact an diagnosis and therapy

Background: Type I allergies are immunological disorders that afflict a qua rter of the world's population. Recombinant allergens have improved the dia gnosis of allergic diseases and allow the formulation of new therapeutic ap proaches. Over 50% of all allergens are of plant origin. Objective: We have applied a novel method of overexpressing plant allergens in the tobacco-re lated species Nicotiana benthamiana. Method:This method is based on the use of a chimeric tobacco mosaic virus that harbors a foreign gene sequence an d directs its transcription after the infection of the host plant. Results: We have expressed the model allergen Bet v 1, the major birch pollen aller gen, and two Hevea brasiliensis latex allergens, the spina-bifida-associate d allergens Hev b 1 and Hev b 3, in N. benthamiana using such a viral vecto r. Bet v 1, Hev b 1 and Hev b 3 produced by this method were recognized by patients' IgE suggesting that the plant-produced allergens were property fo lded. Nonpurified Bet v 1 expressed in N. benthamiana leaves had the same i mmunogenicity as purified Bet v 1 expressed in Escherichia coli or natural Bet v 1 when tested in a murine model of type I allergy. Conclusion: We con clude that this plant expression system offers a viable alternative to ferm entation-based production of allergens in bacteria or yeasts. Copyright (C) 2001 S. Karger AG, Basel.