Maintenance of in Vivo Tolerance by Persistence of Antigen

Abstract
T cells of the immune system respond only to foreign antigens because those cells with reactivity for self proteins are either deleted during their development or rendered non-responsive (anergic). The maintenance of the nonresponsive state was found to require the continual exposure of the anergic T cells to antigen. When anergic T cells were removed from the self antigen by adoptive transfer to a mouse strain lacking the antigen or by in vitro culture, nonresponsiveness was reversed and the anergic cells returned to normal functional status.