How to detect eosinophil ETosis (EETosis) and extracellular traps

Area of Science:

• Immunology
• Cell Biology

Background:

• Eosinophils, though short-lived leukocytes, have critical roles in homeostasis and diseases like allergy and infection.
• Eosinophil Extracellular Trap cell death (EETosis) is an active cytolytic process releasing eosinophil extracellular traps (EETs) and cellular contents.
• EETosis is increasingly recognized for its pathological contribution, notably its association with Charcot-Leyden crystals in eosinophilic inflammation.

Purpose of the Study:

• To review current methods for visualizing EETs and EETosis in both clinical samples and in vitro studies.
• To highlight the common features of EETosis, such as active eosinophil lysis and the release of granular and chromatin structures.
• To underscore the need for further research into EETs/EETosis due to their significant biological implications.

Main Methods:

• Utilizing simple chemical or fluorescence staining techniques.
• Employing immunostaining for specific marker identification.
• Applying electron microscopy for high-resolution visualization of cellular structures.
• Examining sample preparation effects on EET visualization, including extracellular space and shear flow.

Main Results:

• EETosis is characterized by active eosinophil lysis releasing cell-free granules and net-like chromatin structures.
• Various visualization methods, including staining and microscopy, can detect EETs/EETosis.
• Sample preparation significantly influences the observed morphology of EETs.

Conclusions:

• EETosis is a crucial mechanism involving eosinophil cell death and the release of extracellular traps.
• Current methods allow for the visualization of EETs/EETosis, though standardization is lacking.
• Further research is essential to fully elucidate the roles of EETs/EETosis in physiological and pathological processes.