Viral infections in the pathogenesis of autoimmune diseases: focus on type 1 diabetes

Susceptibility to autoimmune diseases is dictated by a complex interplay of genetic determinants and environmental factors. Viral infections have long been suspected to be involved in the etiology of several autoimmune disorders. In particular, the incidence of type 1 diabetes worldwide is increasing at a yearly rate that cannot be solely attributed to genetic changes in the population and environmental factors certainly play an important role in the pathology of this autoimmune disease. In this review, we will focus our discussion on the evidence supporting a role for viral infections in the pathology of viral induced autoimmunity based on the example of type 1 diabetes. We will place a particular emphasis on the major candidate viruses and on the current state of knowledge regarding the mechanisms responsible for the induction of autoimmunity following viral infections. The lessons learned from type 1 diabetes provide a great framework of knowledge that can be applied to most viral-induced autoimmune diseases.