An international team of researchers led by Bart Roep of the Duarte-based City of Hope has been able to justify an alternative theory about the cause of Type 1 diabetes, according to results of a study published Monday in the journal Nature Medicine.
Roep, along with researchers from the Leiden University Medical Center in the Netherlands, have found a mechanism in which stressed beta cells are actually causing the immune response that leads to Type 1 diabetes, previously known as juvenile diabetes.
“Our findings show that Type 1 diabetes results from a mistake of the beta cell, not a mistake of the immune system,” Roep said. “The immune system does what it is supposed to do, which is respond to distressed or unhappy tissue, as it would in infection or cancer.”
In order to gain a better understanding of why the immune system attacks the body’s own source of insulin, the pancreatic beta cells in the islets of Langerhans, the team took some clues from cancer molecules that are targeted by the immune system after successful treatment of the cancer with immunotherapy.
One of these cancer targets is a so-called nonsense protein, resulting from a misreading of a DNA sequence that makes a nonfunctional protein.
The same type of protein error is also produced by the beta cells in Type 1 diabetes. Therefore, Roep and the other researchers believe it is a wrong read of the insulin gene itself that proves to be a major target of the immune system.
This error product of the insulin gene is made when beta cells are stressed, Roep said.
Roep said the results of the study give new insight for his work in developing new vaccines to desensitize the immune system so it will tolerate islets again, as well as for research into combining immunotherapy with more traditional diabetes treatments to reinvigorate islets.
“Our goal is to keep beta cells happy,” Roep said. “So we will work on new forms of therapy to correct the autoimmune response against islets and hopefully also prevent development of Type 1 diabetes during anti-cancer therapy.”
—City News Service