Medullary thymic epithelial cells (mTECs) represent a unique stromal cell population of the thymus which plays an essential role in the establishment of central tolerance. Therefore, mTECs rank among cells relevant for the development of functional mammal immune system.
T cell precursors rise in bone marrow and migrate through the bloodstream to the thymus for further development. During their maturation in the thymus, they undergo a process called V(D)J recombination which conducts the development of T cell receptors (TCRs). The mechanism of this stochastic process enables on one hand the generation of vast repertoire of TCRs, however, on the other hand causes also origin of so called "autoreactive T cells" which recognize self antigens via their TCRs. Autoreactive T cells must be eliminated from the body or skewed into the T Regulatory cells (TRegs) lineage to prevent manifestations of autoimmunity. mTECs possess the ability to deal with these autoreactive clones via mediation of the processes of central tolerance, namely clonal deletion or T regulatory cells selection, respectively.
N.B.: All the below cited references utilized mouse as a model organism.