▪ Abstract Apoptosis of mature T lymphocytes preserves peripheral homeostasis and
tolerance by countering the profound changes in the number and types of T cells stimulated
by diverse antigens. T cell apoptosis occurs in at least two major forms: antigen-driven and
lymphokine withdrawal. These forms of death are controlled in response to local levels of IL-
2 and antigen in a feedback mechanism termed propriocidal regulation. Active antigen-
driven death is mediated by the expression of death cytokines such as FasL and TNF. These …