Tomato (Solanum esculentum) elicits allergic symptoms such as oral allergy syndrome, contact urticarial syndrome or anaphylactic shock in sensitized patients. So far at least 13 proteins have been associated with IgE-binding in tomato. Four of these IgE-binding proteins have been classified as allergens. Over the last years we have established tomato fruits as models to test molecular strategies to generate hypoallergenic food. Major aims of this sub-project are (i) to provide proof of principle that RNAi technologies can be used to generate hypoallergenic food even if multiple allergens need to be targeted and if allergens with essential cellular functions are involved, (ii) to explore new technologies for targeted genome modifications and (iii) to investigate allergenic structures of profilin by random mutagenesis combined with functional selection in yeast. To achieve our first aim we have developed a breeding scheme to combine down-regulation of up to eight IgE-binding proteins from tomato. The second goal will be reached by using customized TALE nucleases for mutagenesis of Lyc e 3. To identify allergenic determinants of profilins in a random fashion we have developed a yeast-based screening platform to allow selection for functional and hypoallergenic profilin variants. This system has successfully been used to identify hypoallergenic Lyc e 1 and will be applied to screen for hypoallergenic profilin variants from other plant sources such as Bet v 2 or Api g 4. In a reverse experiment we will mutagenize yeast profilin to test whether it is possibly to convert a non-allergenic protein into an allergen.
DFG Programme
Research Grants
