The immune pathogenesis of experimental autoimmune encephalomyelitis: lessons learned for multiple sclerosis?

Experimental autoimmune encephalomyelits (EAE) has been widely studied as a model for multiple sclerosis (MS). EAE also holds a special place in basic autoimmune research. It is induced by immunizing healthy, naïve mice with neuroantigen. Unlike in spontaneous autoimmune models, one can therefore clearly define the initiation time point, the inducing antigen, the circumstances of the immunization that elicit a pathogenic--or nonpathogenic--T cell response, and many other parameters that are required for the induction and perpetuation of autoimmune central nervous system pathology. In the following, we will provide an overview of our current understanding of the discrete steps that lead to the pathogenesis of EAE, and we will highlight several junctions at which the perpetuation or abortive course of the disease is defined. It has become abundantly clear that the induction of a pathogenic CD4+ T cell response is a necessary requirement for the induction of EAE. However, many downstream mechanisms need to be considered if we want to understand the pathomechanisms that define the variable outcomes of EAE, and by inference, of MS.