Activation of Interferon-γ Inducing Factor Mediated by Interleukin-1β Converting Enzyme

Abstract
The interleukin-1β (IL-1β) converting enzyme (ICE) processes the inactive IL-1β precursor to the proinflammatory cytokine. ICE was also shown to cleave the precursor of interferon-γ inducing factor (IGIF) at the authentic processing site with high efficiency, thereby activating IGIF and facilitating its export. Lipopolysaccharide-activated ICE-deficient (ICE−/−) Kupffer cells synthesized the IGIF precursor but failed to process it into the active form. Interferon-γ and IGIF were diminished in the sera of ICE−/− mice exposed to Propionibacterium acnes and lipopolysaccharide. The lack of multiple proinflammatory cytokines in ICE−/− mice may account for their protection from septic shock.
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