EN
Until recently, the traditional view was that tolerance to self antigens was maintained by a combination of physical deletion intrathymically and functional deletion in the periphery of autoreactive T cells. There is now, however, abundant evidence that the normal T cell repertoire contains overtly autoreactive T cells whose pathogenic potential is held in check by the activity of a distinct subset of peripheral T cells, so called regulatory or suppressor T cells. This article examines data from one model of rodent autoimmunity, where autoimmune pathology develops following thymectomy and irradiation of normal laboratory rats, which characterise the development and function of these so called regulatory T cells.