Eosinophils

  • Major function in allergic reactions and protection from parasitic infections; regulated by TH2 cytokines (IL-5); weakly phagocytic
  • Harbor granules containing major basic protein (MBP), eosinophilic cationic protein (ECP), eosinophil peroxidase (EPO), eosinophil-derived neurotoxin (EDN): all released upon activation; MBP induces mast/basophil degranulation
  • Major source of cytokines: chemokines (eotaxin, MIP, RANTES), lipid mediators (leukotrienes, platelet-activating factor), cytokines (IL 2–6, 8, 12, IFN γ, TNF α), cytotoxic products (MBP, EPO, EDN, ECP), and neuromediators (substance P, VIP)