EosinophilDerived

Eosinophil-derived refers to substances produced by eosinophils, a type of granulocytic white blood cell involved in host defense and inflammatory responses. Eosinophils store a set of granular proteins in their cytoplasm and can release them through degranulation and piecemeal degranulation upon activation by cytokines, parasites, or immune complexes. The release of these proteins contributes to antimicrobial activity but can also cause tissue damage and remodeling in allergic and eosinophil-associated diseases.

Prominent eosinophil-derived proteins include major basic protein (MBP), eosinophil cationic protein (ECP), eosinophil-derived neurotoxin (EDN), and eosinophil peroxidase (EPO). MBP is a highly basic protein that is toxic to parasites and can disrupt epithelial integrity. ECP is a cationic ribonuclease with antimicrobial properties and cytotoxic potential. EDN (RNase2) is an RNase with antiviral activity and neurotoxic effects in experimental settings. EPO catalyzes reactions that generate reactive oxidants and contributes to host defense as well as tissue injury. These molecules can be measured as biomarkers of eosinophilic inflammation in blood, sputum, or tissue.

Functionally, eosinophil-derived proteins participate in defense against helminths and certain infections, but their excessive or misdirected release is implicated in the pathophysiology of asthma, nasal polyps, atopic dermatitis, and hypereosinophilic syndromes. Therapeutic strategies targeting eosinophils or their mediators, such as IL-5 pathway inhibitors, reflect the role of eosinophil-derived components in disease processes. Research continues to characterize specific roles, interactions with other immune pathways, and context-dependent effects in health and disease.