ALTERED CYTOKINE EXPORT AND APOPTOSIS IN MICE DEFICIENT IN INTERLEUKIN-1-BETA CONVERTING-ENZYME

The interleukin-1 beta (IL-1 beta) converting enzyme (ICE) processes t he inactive IL-1 beta precursor to the proinflammatory cytokine. Adher ent monocytes from mice harboring a disrupted ICE gene (ICE(-/-)) did not export IL-1 beta or interleukin-1 alpha (IL-1 alpha) after stimula tion with lipopolysaccharide. Export of tumor necrosis factor-alpha an d interleukin-6 (IL-6) from these cells was also diminished. Thymocyte s from ICE(-/-) mice were sensitive to apoptosis induced by dexamethas one or ionizing radiation, but were resistant to apoptosis induced by Fas antibody. Despite this defect in apoptosis, ICE(-/-) mice proceed normally through development.