To provide protection against all foreign pathogens one can possibly encounter during their
lifetime, the T cell repertoire has to be as diverse as possible. At the same time, it is
desirable that the T cell repertoire remains unresponsive towards healthy tissues. To realize
this self/nonself discriminatory property, T cells undergo tightly controlled selection
processes during maturation in the thymus. The key parameter determining the outcome of
these selection processes is the avidity of the T cells for self-MHC/self-peptide complexes …