Central tolerance matters

Abstract

In this issue of Immunity, Anderson et al. provide another clue to the riddle that is Aire--why do human beings and mice lacking Aire develop diffuse and pathogenic autoimmunity? They find that Aire influences central tolerance not only by promoting the expression of peripheral self-proteins in thymic medullary epithelial cells (MECs) but also by furnishing these cells with the apparatus for effective antigen presentation ().