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

Antigen receptor-directed suicide plays an important role in the elimination of potentially autoaggressive immature T cells during thymic differentiation. Here we demonstrate evidence for a second pathway of receptor-directed suicide in mature T cells that is missing in a mutant strain (gld) of mice with an ''autoimmune'' lymphoproliferative syndrome. 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 with this mutation. These results support the significance of receptor-directed suicide in the mature T cell compartment and suggest that the immune system may use three independent pathways for regulating programmed cell death in shaping and controlling the immune response.