NEWS RELEASE, 10/19/97
FOR IMMEDIATE RELEASE
Researchers from UC Berkeley, UC San Francisco and UC Davis will report successful application of the new method to lower the allergenicity of milk at the Oct. 19-24 meeting of the International Congress of Allerology and Clinical Immunology in Cancun, Mexico. UC Berkeley has filed for patents on the discoveries, and is in the process of identifying organizations to develop commercial applications.
The new technology exploits the ability of a naturally occurring product called thioredoxin to make some proteins, such as those found in wheat and milk, more digestible and less allergenic. These components of foods, called allergens, normally trigger an allergic response in individuals with a particular food sensitivity. Thioredoxin works by changing the shape of proteins in problem foods such that they lose much of their ability to trigger allergies. The treated proteins are also easier to digest.
"If things work out, this new biotechnology could make life easier for millions suffering from food allergies," said Bob B. Buchanan, a professor of plant and microbial biology with UC Berkeley's College of Natural Resources. "We've found that people who have learned about this approach have been very excited because nothing like this has been done before. We could save lives and reduce illnesses for millions of human and canine food allergy sufferers worldwide simply through using a compound present in the diet to alter food allergens."
Buchanan's collaborators include G. del Val, B. C. Yee and R. Lozano of UC Berkeley, as well as allergy specialist Dr. O. L. Frick of the UC San Francisco Department of Pediatrics and Dr. R. Ermel of the UC Davis School of Veterinary Medicine.
Food allergies afflict about 8 percent of all toddlers in the U.S. and as many as 25 percent in Japan. While at present the only guaranteed means of treating a food allergy is by elimination of the problem food from the diet, Buchanan said thioredoxin might change this.
In highly food-sensitive dogs, Buchanan and his colleagues have shown as much as a 300-fold reduction in allergenicity for milk pretreated with thioredoxin.
"This means it takes 300 times more allergen to get an adverse effect after the food has been pretreated with thioredoxin," said Buchanan.
Buchanan said that as many as nine in 10 dogs experienced a significant relief of the problem in response to the treatment.
Although human trials have not begun, "dogs are very similar to humans for allergies," said Frick, "just amazingly close, actually."
If human trials prove as promising as the ongoing studies with dogs, thioredoxin could minimize human allergy problems and make dairy products available to countless infants and adults worldwide. Future trials may also prove the thioredoxin technique useful for other foods such as eggs and nuts.
Thioredoxin might help alleviate symptoms not only for allergy sufferers, but also for a significant portion of the 300,000 people in the U.S. who have celiac disease -- a poorly understood reaction to wheat. Such individuals cannot consume most cereals without suffering from symptoms ranging from mild headache to sudden loss of consciousness.
"Most people know someone who has celiac disease," said Buchanan. "Life for these people is hard and can be filled with fear at meal time as they have severe reactions to so many foods."
The present allergy work grew out of three decades of fundamental research on the role of thioredoxin in plants. Thioredoxin was previously known to be an important biochemical molecule, implicated in such processes as seed germination and the ability of plant chloroplasts to recognize night from day.
Thioredoxin targets bonds between two sulfur atoms within a single protein chain. Such bonds are famous in the world of biochemistry as being difficult to break under normal body conditions. Thioredoxin, however, can readily break these bonds. It attacks the link between the two sulfur atoms, adding a hydrogen to each one, a chemical process scientists call reduction.
Not surprisingly, these bonds are found
in proteins that are hard to digest -- the same proteins which are also
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