Transgenic tomatoes could cut allergic reactions
allergen, profilin, represents "a future trend in allergen
avoidance," said the German researchers behind a new study.
But despite this offering an alternative approach, one of the main challenges of this approach will not be technical but consumer attitudes and regulations regarding genetically modified organisms (GMO), particularly in Europe.
An estimated four per cent of adults and eight per cent of children in the 380m EU population suffer from food allergies, according to the European Federation of Allergy and Airways Diseases Patients' Associations.
Dr. Ronald van Ree from the University of Amsterdam recently told attendees at the BA Festival of Science in England that recent advances in biotechnology have identified the specific molecules in foods that induce food allergies. Such knowledge could also lead to genetic engineering techniques to change these molecules so that they no longer cause an allergic response, he said.
And the research, by scientists at the Friedrich-Alexander University Erlangen-Nuremberg and Paul-Ehrlich-Institut, represents one of the first reports of a genetically engineering to reduce a food allergy.
While considerably less common than peanut or cows milk allergy, up to 16 per cent of people with food allergy are said to be allergic or sensitive to tomatoes, "indicating that tomato is a relevant allergenic food," said lead author Lien Quynh Le in the Journal of Allergy and Clinical Immunology (published on-line ahead of print, doi:10.1016/j.jaci.2006.06.031).
Indeed, "three tomato allergens have been identified thus far and were included in the official allergen list by the International Union of Immunological Societies Allergen Nomenclature Subcommittee," said Quynh Le.
The researchers used the RMA interference approach to silence two genes (Lyc e 1.01 and Lyc e 1.02) associated with profilin production, a small protein that is said to contribute to fruits and vegetables allergy, and produce transgenic tomatoes.
The resultant GM tomatoes were found to have contain about 10 per cent of the profilin levels of 'wild-type' tomatoes.
Extracts of both the GM and wild-type tomatoes were prepared and 16 people with diagnosed tomato allergies were recruited to test for an allergic response using a skin-prick test.
The researchers report that when volunteers were sensitive to only one tomato allergen, the GM tomatoes significantly improved the allergic response. However, when patients were sensitive to several tomato allergens the response was less pronounced.
Lien Quynh Le and her co-workers said that to create truly hypoallergenic tomatoes, the described strategy of using RNAi would have to be extended to silence multiple genes.
"Our findings demonstrate the feasibility of creating low-allergenic food by using RNA interference (RNAi). This approach constitutes a future trend in allergen avoidance," said the scientists.
