Bone marrow stem cells may help treat inflammatory bowel
disease
Washington, Aug 21 : A new study in mouse model has shown that infusions of a
particular bone marrow stem cell appears to control inflammatory bowel disease.
Researchers at the Massachusetts General Hospital (MGH) found that mesenchymal stem
cells (MSCs), known to control several immune system activities, allowed the regeneration
of the gastrointestinal lining in mice with a genetic mutation leading to multiorgan
autoimmune disease.
"Our findings suggest that MSC therapy could become a useful treatment for inflammatory
bowel disease," said lead author Biju Parekkadan, PhD, of MGH Center for Engineering in
Medicine.
"Several previous studies have observed these cells' ability to inhibit specific
subsets of T cells and relieve symptoms in particular autoimmune disorders. But this is
the first demonstration of their ability to suppress a broad-based autoimmune reaction and
protect gastrointestinal tissue," Parekkadan added.
Found in the bone marrow, MSCs give rise to tissues supporting blood cell development
and secrete factors that can modulate several immune system activities. Their use has
recently received FDA approval to treat severe graft-versus-host disease in children.
The new study was designed to find MSCs' therapeutic potential in a model of multiorgan
autoimmune disease.
The researchers used a strain of mice in which a genetic mutation leads to deficiency
in regulatory T cells, which suppress the activity of self-reactive immune cells,
resulting in overwhelming autoimmune disease.
The mice were treated with infusions of either MSCs or regulatory T cells, and a week
later the researchers examined the effects on tissues from the pancreas, the liver and the
distal ileum - the lower end of the small intestine - which are usually attacked by
autoimmune reactions.
While little improvement was seen in the pancreatic or liver tissue, in four of the six
MSC-treated mice, intestinal tissues appeared almost identical to those of normal
mice.
Structural defects seen in the intestinal lining of untreated autoimmune mice had
disappeared in the MSC-treated mice, an improvement seen in only one of six mice treated
with regulatory T cells.
Analysis of the animal's lymph nodes revealed that MSC treatment produced a significant
reduction in inflammation.
Surprisingly, cell-tracking studies indicated that the MSCs - which were administered
by infusion into the peritoneum, the membrane lining the abdominal cavity - moved into
abdominal lymph nodes rather than to the intestine itself.
The presence of MSCs was associated with a reduction of activated T cells and changes
in other indicators of immune system activity, indicating suppression of the
out-of-control immune reaction.
The study is published in the journal Stem Cells.
--ANI
