Title: Eosinophil-Derived Neurotoxin / RNase 2: Connecting the Past, the Present and the Future
VOLUME: 9 ISSUE: 3
Author(s):H. F. Rosenberg
Affiliation:Laboratory of Allergic Diseases, Building 10, Room 11C215, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, USA.
Keywords:Inflammation, Ribonuclease, Toll-like receptor, Dendritic cell, Leukocyte
Abstract: The eosinophil-derived neurotoxin (EDN, also known as eosinophil protein-X) is best-known as one of the four major proteins found in the large specific granules of human eosinophilic leukocytes. Although it was named for its discovery and initial characterization as a neurotoxin, it is also expressed constitutively in human liver tissue and its expression can be induced in macrophages by proinflammatory stimuli. EDN and its divergent orthologs in rodents have ribonuclease activity, and are members of the extensive RNase A superfamily, although the relationship between the characterized physiologic functions and enzymatic activity remains poorly understood. Recent explorations into potential physiologic functions for EDN have provided us with some insights into its role in antiviral host defense, as a chemoattractant for human dendritic cells, and most recently, as an endogenous ligand for toll-like receptor (TLR)2.