INTERFERON EXPRESSION IN THE PANCREASES OF PATIENTS WITH TYPE-I DIABETES

We have used a reverse transcriptase-polymerase chain reaction (RT-PCR ) protocol to examine the expression of cytokines in the pancreases an d islets of patients with type I diabetes, We detect a significant inc rease in the level of expression of interferon (IFN)-alpha in the panc reases of the diabetic patients as compared with the control pancrease s, In contrast, IFN-beta was detected at comparable levels in both gro ups, while IFN-gamma was detected in three of four control pancreases and one of four pancreases from the diabetic individuals, The IFN-alph a cDNAs generated by the RT-PCR were cloned and sequenced to determine which alpha-subtypes mere being expressed, We found that the repertoi re of subtypes was quite Limited in any one individual (diabetic or no t), although each individual was different with respect to the pattern of subtypes expressed, We also examined these pancreases for the expr ession of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-2, IL-4, and IL-6, We found no detectable expression of TNF-alpha o r IL-2 in any pancreases, and the expression of the other cytokines wa s variable, with no pattern emerging from the comparison of the diabet ic and nondiabetic individuals, We conclude that, of the cytokines exa mined, only IFN-alpha was significantly increased in the diabetic pati ents, a result that is consistent with the possibility that this cytok ine is directly involved in the development of type I diabetes.