Interleukin (IL)-4 antagonism increases IL-10 production by na�ve T lymphocytes*1Association with apoptosis

Conclusions NaïVe T cells undergo apoptosis if not differentiated into effector T cells by foreign antigen or protected by low affinity engagement of their T cell receptor by MHC/self antigen. Apoptosis is delayed by the autocrine effects of constitutively produced IL-4. Agents which block IL-4 in the immune synapse (anti-IL4R) as opposed to secreted distally-acting forms of IL-4 (sIL-4R) accelerate the development of apoptosis and thereby promote IL-10 secretion.