Three protein fragments are looking like the guilty parties in celiac disease, an intestinal ailment that affects as many as one in 133 people in the United States. These partial proteins, or peptides, are the components of gluten in wheat, rye and barley that trigger the immune systems of celiac patients, damaging the small intestine.
Pinpointing these peptides opens the way for development of a vaccine that might help celiac patients tolerate these foods. The research team, led by gastroenterologist Robert Anderson of the Walter and Eliza Hall Institute of Medical Research in Parkville, Australia, is now pursuing this line of work.
As it is, celiac patients deal with their condition by avoiding wheat, rye and barley. Most people digest these cereals effortlessly, but people with celiac disease have a genetic predisposition that causes an aberrant immune response to the gluten in the grains, damaging the walls of the small intestine. Celiac disease cancause painful bloating, diarrhea, constipation, lethargy and other problems.
Researchers fed more than 200 celiac patients wheat, barley and rye for three days, mobilizing the patients' immune T cells to mount an attack on gluten. Using these T cells, scientists measured the patients' immune reactions to 2,700 compounds from gluten.
While dozens of peptides elicited some response, three stood apart. One appears in a type of wheat gluten.
Another is found in rye gluten. And a third shows up on certain gluten proteins in all three cereals.
Nexpep, a biotech firm cofounded by Anderson, has begun a clinical trial using the peptides in avaccine that aims to help celiac patients tolerate the compounds.
By Nathan Seppa
August 14, 2010