ISLET EXPRESSION OF INTERFERON-ALPHA PRECEDES DIABETES IN BOTH THE BBRAT AND STREPTOZOTOCIN-TREATED MICE

The mechanism(s) leading to beta cell dysfunction in type I diabetes h as not been defined. We have investigated whether islet expression of IFN alpha could be a cause of the lesions that are hallmarks of type I diabetes. Streptozotocin induces the expression of interferon-alpha b y pancreatic islets prior to the diabetes induced by streptozotocin. I ncreased IFN alpha, induced by poly I/C or expressed from a transgene will exacerbate the diabetogenic effects of streptozotocin. In another rodent model of type I diabetes (the BB rat), islet expression of IFN alpha precedes lymphocytic infiltration and diabetes. As in the strep tozotocin model, in the BB rats poly I/C will induce islet expression of IFN alpha and accelerate the onset of diabetes. These results are c onsistent with the hypothesis that islet expression of IFN alpha parti cipates in causing type I diabetes.