Molecular mimicry and diabetes

Insulin-dependent diabetes (IDDM) often develops early in life and is associated with lifelong insulin treatment, a reduced life span, and serious long-term complications (Borch-Johnsen et al. 1986). Other forms of diabetes exist (National Diabetes Data Group 1979), e.g., noninsulin-dependent diabetes, maturity onset diabetes in the young (MODY), and insulin-resistant diabetes associated with a decreased function of the insulin receptor. In this review we discuss the findings of molecular mimicry between virus proteins and autoantigens in IDDM and insulin-resistant diabetes associated with antibodies to the insulin receptor and the implications for its etiology and pathogenesis. Autoimmunity has in both diseases been shown to be important in the pathogenesis, but little is known about the initiating factors. Observations and analysis of homologies between viral antigens and autoantigens involved in the disease offer an unique way of probing for possible etiologic agents.