Eosinophils from Physiology to Disease: A Comprehensive Review
Table 1
Functional characterisation of eosinophil granules.
Primary granules
Galectin 10 (CLC protein)
Charcot-Leyden crystals formation in tissues and fluids lysophospholipase activity Potential immunoregulatory function towards T cells
Specific/crystalloid granules
Crystal core
MBP
Disrupts lipid layers and increases membrane permeability → cytotoxic to host cells and pathogens Component of EETs Basophils, neutrophils & mast cells activation and degranulation Neuroprotective effect Epithelial activation and expression of tissue remodelling factors Increases smooth muscle reactivity Inhibits M2 muscarinic receptors
Matrix
EDN
(potent) RNAse → antiviral role (ssRNA viruses) Neurotoxicity (Purkinje cells) Dendritic cells chemotaxis, maturation and activation → proliferation of T and B cells
ECP
(Weak) RNAse Cytotoxic to host cells and pathogens (parasites, viruses, bacteria) Neurotoxicity (Purkinje cells) Membrane disruption Component of EETs
EPO
Generation of ROS toxic to extracellular pathogens (helminth parasites, bacteria) Pro- and anti-inflammatory effects Epithelial activation and expression of tissue remodelling factors Lipid peroxidation
Lipid bodies
Arachidonic acid derivatives (LT, PG, TX)
Promotion of acute and late hypersensitivity responses Prominent role in airways inflammation
