AUTOIMMUNE GLD MUTATION UNCOUPLES SUICIDE AND CYTOKINE PROLIFERATION PATHWAYS IN ACTIVATED, MATURE T-CELLS

Antigen receptor-directed suicide plays an important role in the elimi nation of potentially autoaggressive immature T cells during thymic di fferentiation. Here we demonstrate evidence for a second pathway of re ceptor-directed suicide in mature T cells that is missing in a mutant strain (gld) of mice with an ''autoimmune'' lymphoproliferative syndro me. The defect is evident within the gld activated T cell and does not require the presence of an antigen-presenting cell for its expression . Receptor-driven suicide is intact in immature T cells of animals wit h this mutation. These results support the significance of receptor-di rected suicide in the mature T cell compartment and suggest that the i mmune system may use three independent pathways for regulating program med cell death in shaping and controlling the immune response.