Abstract
Viral infections were described to be one of the major triggers of autoimmune diseases in individuals with a genetic predisposition. The functional impairment of immune tolerance involves multiple steps and to date, several principles were discussed.
The principles of virus-induced autoimmunity include particularly molecular mimicry, bystander activation and determinant spreading. It is generally accepted that structurally complex viruses are more likely to cause cross-reactivity of the immune system with self-structures.
The most important role of viral agents in the initiation of autoimmune disease was described in multiple sclerosis, type 1 diabetes mellitus and Guillain-Barre syndrome. However, the clinical manifestation of the disease largely depends on the individual properties of the immune system, the microbiome setting and other environmental factors.
In this review, we describe the major mechanisms by which viruses break down the immune tolerance and trigger autoimmunity. We also describe selected autoimmune diseases and discuss their association to specific viral infections.