Antiautoimmune Drug Treatment Combined with Bone Marrow Transplant Cures Mouse Model of Type I Diabetes

Treatment with a drug to block autoimmune attack combined with transplantation of adult bone marrow cells or purified bone marrow progenitor cells restored the population of insulin-producing pancreatic beta cells and cured a mouse model of type I diabetes.

Investigators at the University of Missouri (Columbia, USA) had previously shown that a peptide drug (Ig-GAD2 ) comprising a 14 amino acid sequence isolated from the enzyme glutamic acid decarboxylase, induced immune modulation in hyperglycemic mice that was able to control pancreatic inflammation, stimulate beta-cell regeneration, and prevent type I diabetes progression. However, this treatment was unable to reverse the course of the disease despite eradication of inflammatory immune cells from the pancreas.

In a paper published in the May 28, 2013, online edition of the journal Diabetes the investigators reported that the reason for this failure was linked to damage done by autoimmune attack to the capillaries that supply blood to the pancreas. To repair this damage they injected diabetic rats with either bone marrow cells or purified bone marrow progenitor cells in combination with Ig-GAD2.

The investigators reported that when the mice received bone marrow cells together with Ig-GAD2, in addition to immune modulation there was concomitant formation of new beta- and endothelial cells in the pancreas. The new beta cells were of host origin while the donor bone marrow cells gave rise to the endothelial cells. On the other hand, transfer of purified bone marrow endothelial progenitors instead of whole bone marrow cells sustained both beta- and endothelial cell formation and reversal of diabetes.

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