Fig. 2
From: Eosinophil extracellular traps in asthma: implications for pathogenesis and therapy
The double-edged sword effect of EETs. EETs are reticular structures composed of DNA, histones, and granulins that are formed by eosinophils and released into the extracellular compartment, forming one of the components of the innate immune response. Components of EETs play an active role in the control of infections by trapping and destroying microorganisms, including viruses, fungi, bacteria, and protozoan pathogens. Although EETs can protect the host from microorganisms, excessive EETs can be harmful to the host. While the early stages of asthma are characterized by an increase in eosinophils, in the severe stage of asthma, activated eosinophils can release excessive amounts of EETs, causing airway epithelial damage and CLC production, making sputum more difficult to cough up, in addition to exacerbating the type 2 inflammatory response by interacting with other immune cells. T2: Type 2; CS: Corticosteroids; EETs: Eosinophil extracellular traps; ECP: Eosinophil cationic protein; MBP: Major basic protein; EDN: Eosinophil-derived neurotoxin; EPO: Eosinophil peroxidase; CLCs: Charcot-Leyden crystals