Mimicking the way to autoimmunity: an evolving theory of sequence and structural homology.

Although the etiology of autoimmune diseases remains largely unknown, a prevailing theory concerns the infection-induced activation of self-reactive lymphocytes via the process of molecular mimicry. Here, we discuss the theory of molecular mimicry and its continued evolution from the initial basic considerations of sequence similarity to the current theories of structural homology. Such findings serve to further our understanding of T-cell receptor degeneracy and might one day provide a direct link between infection and autoimmune disease.