Enteroviruses and T1D: Is It the Virus, the Genes or Both which Cause T1D

Type 1 diabetes (T1D) is a chronic autoimmune disorder that results from the selective destruction of insulin-producing beta-cells in the pancreas. Up to now, the mechanisms triggering the initiation and progression of the disease are, in their complexity, not fully understood and imply the disruption of several tolerance networks. Viral infection is one of the environmental factors triggering diabetes, which is initially based on the observation that the disease's incidence follows a periodic pattern within the population. Moreover, the strong correlation of genetic susceptibility is a prerequisite for enteroviral infection associated islet autoimmunity. Epidemiological data and clinical findings indicate enteroviral infections, mainly of the coxsackie B virus family, as potential pathogenic mechanisms to trigger the autoimmune reaction towards beta-cells, resulting in the boost of inflammation following beta-cell destruction and the onset of T1D. This review discusses previously identified virus-associated genetics and pathways of beta-cell destruction. Is it the virus itself which leads to beta-cell destruction and T1D progression? Or is it genetic, so that the virus may activate auto-immunity and beta-cell destruction only in genetically predisposed individuals?