[Viruses as the etiological factor of type 1 diabetes. Animal models]

Type 1 diabetes (TID) results from the destruction of pancreatic beta-cells. In spite of genetic pre-disposition, being the major component for the development of this type of diabetes, nongenetic factors also play an important role in the disease development. Among these factors viruses are implicated in the pathogenesis of TID. Basing on the literature data we have attempted to elucidate possible role of viruses in TID pathogenesis. Viruses may be involved in the TID pathogenesis in at least two distinct mechanisms. Firstly, viruses may trigger beta-cell-specific autoimmunity with or without direct infection of beta-cells. Secondly, viruses may directly infect and destroy beta-cells resulting in TID. Moreover viruses not only cause diabetes, but also may prevent from the disease in animals susceptible to diabetes. Further studies are necessary to understand the mechanisms of the pathogenesis of human virus-induced TID.