Thymus is a primary lymphoid organ responsible for T cell development and despite this unique function, it is a target organ in many different diseases. Thymus microenvironment is composed by lymphocytes and stromal components. In the stromal compartment we can find epithelial cells which are divided in two subtypes: cortical and medullar thymic epithelial cell. Such cells are important to thymocyte maturation and education as they provide the essential signals to T cell development. Previously, we have reported that during the clinical course of EAE, which is a model of a T CD4+ lymphocyte-mediated autoimmunity disease, thymus present important alterations in lymphocyte compartment and neuronal molecules.In this project, we pretended caracterize the alterations in thymus stromal compartment in order to a better undestanding of thymus during an autoimmune disease.