Embargoed until 2 p.m. EDT
NSF PR 02-77 - September 26, 2002
1. Wheat-based foods
are broken down in the stomach and the
upper part of the small intestine called
the duodenum. Gluten is broken down in
2. Some of the partially
digested food travels to the next segment
of the small intestine called the jejunum.
3. In the jejunum, structures
called villi with surface-bound enzymes
break food down into complex molecules
the body absorbs.
4. Gluten adheres to
the tips of villi where enzymes break
it down into simpler molecules called
peptides. Some of the peptides, called
33-MER, cannot be broken down any further.
This is true for all persons whether they
suffer from celiac sprue or not.
5. Absorption cells in
the gut lumen absorb 33-MER peptides and
pass them into the tissues of the lamina
propria. Antigen presenting cells (APC),
part of the body's immune system, target
foreign substances in the body for response
by the immune system. APC do this by binding
with the foreign substance, and then send
biochemical signals to white blood cells
to attack. In nearly all people with celiac
sprue, APC bind with 33-MER only if the
APC carry a protien called DQ2.
6. Once the intestinal
wall absorbs 33-MER peptides, APC in celiac
sprue patients signal white blood cells
to attack. The result is eventual desctruction
of absorption cells and villi in the intestinal
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