Authors:
Bill B Chen, Tiffany A Coon, Jennifer R Glasser, Bryan J McVerry, Jing Zhao, Yutong Zhao, Chunbin Zou, Bryon Ellis, Frank C Sciurba, Yingze Zhang, & Rama K Mallampalli
Summary:
Uncontrolled activation of tumor necrosis factor receptor–associated factor (TRAF) proteins may result in profound tissue injury by linking surface signals to cytokine release. Here we show that a ubiquitin E3 ligase component, Fbxo3, potently stimulates cytokine secretion from human inflammatory cells by destabilizing a sentinel TRAF inhibitor, Fbxl2. Fbxo3 and TRAF protein in circulation positively correlated with cytokine responses in subjects with sepsis, and we identified a polymorphism in human Fbxo3, with one variant being hypofunctional. A small-molecule inhibitor targeting Fbxo3 was sufficient to lessen severity of cytokine-driven inflammation in several mouse disease models. These studies identified a pathway of innate immunity that may be useful to detect subjects with altered immune responses during critical illness or provide a basis for therapeutic intervention targeting TRAF protein abundance.
Source:
Nature Immunology; 14, 470-479 (03/31/13)