www.checkbiotech.org ; www.raupp.info ; www.czu.cz

Scientists have identified a new gene in peanuts that codes for a protein
with no apparent allergic effects, research that opens up the possibility of
allergen-free GM nuts, November 2006 by Stephen Daniells.

The identification of the new gene, called ara h 3-im, by researchers from
the University of Florida offers some hope for estimated 2.5 million people
in Europe and the US now vulnerable to the food allergy.

"If it is true that Ara h 3-im has lower allergenic properties than other
Ara h 3 proteins, this study may provide the information necessary to
produce a hypoallergenic peanut through silencing of the major allergens and
selecting for the reduced allergenic polypeptides via mutational breeding
and/or genetic engineering," wrote authors I-H Kang and M. Gallo.

While it is too early to tell if such a peanut will be available for the
food industry in the foreseeable future, escalating incidences of food
allergies in Europe and the desire to avoid potentially harmful consumer
confusion underpinned changes to the Labelling Directive 2000/13/EC due to
enter into force this month that essentially flag up to the consumer
possible allergens in a food product.

The amendment heralds the mandatory inclusion on food labels of the most
common food allergen ingredients and their derivatives: cereals containing
gluten, fish, crustaceans, egg, peanut, soy, milk and dairy products
including lactose, nuts, celery, mustard, sesame seed, and sulphites.

There is no current cure for food allergy and vigilance by an allergic
individual is the only way to prevent a reaction but a peanut allergy can be
so severe that only very tiny amounts can be enough to trigger a response.

"Although about 20 peanut allergens have been reported, Ara h 1, Ara h 2 and
Ara h 3 are classified as important major allergens which are recognized by
more than 50 per cent of peanut allergic patients," explained the
researchers.

"Ara h 1 and Ara h 2 are recognized by 70 to 90 per cent of patients with
peanut allergy, and Ara h 3 is recognized by serum immunoglobulin E from
approximately 44 to 54 per cent of different patient populations with a
history of peanut sensitivity," they said.

The new research, published in the journal Plant Science, reports that a
previously unidentified complementary/cloned DNA (cDNA) produces a protein
with potentially reduced allergenicity.

The researchers report that Ara h 3-ims novel N-terminal sequence is
different and distinct from the other allergens. This changes the proteins
ability to bind to immunoglobulin E (IgE), an antibody that is capable of
initiating powerful immune responses.

Using a technique called immunoblotting the researchers report that these
distinct differences were translated into the Ara h 3-im polypeptide not
being recognized by IgE, isolated from blood taken from peanut sensitive
patients.

This opens up the opportunity to genetically modify or breed mutationally a
peanut with the allergen Ara h 3 replaced by the non-allergen Ara h 3-im.

"Initial results indicate that Ara h 3-im has potentially lower allergenic
properties than previously characterized peanut allergens which may aid in
the production of a hypoallergenic peanut," concluded the researchers.

Significant further research is needed, but one of the main challenges to
the continued development of this technique will be consumer acceptance,
particularly in Europe, and most notably in the UK, if the research follows
the genetically modified route.

[www.foodnavigator.com]

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