Calcium ionophore-activated platelets induce eosinophil extracellular trap formation

Area of Science:

• Immunology
• Cell Biology
• Allergy Research

Background:

• Platelets modulate inflammation via granule release and microparticle formation.
• The interaction between platelets and eosinophils is implicated in allergic airway inflammation.
• Eosinophil Extracellular Traps (EETs) are DNA fibers released by activated eosinophils.

Purpose of the Study:

• To investigate if activated platelets can induce eosinophil extracellular trap (EET) formation.
• To explore the mechanisms underlying platelet-induced EET formation.

Main Methods:

• Platelets were activated using A23187, thrombin, or ADP.
• Platelet conditioned medium and pellets were applied to eosinophils to assess EET formation.
• EET formation was analyzed for dependency on NADPH oxidase (NOX) and inhibition by necroptosis pathway inhibitors.

Main Results:

• A23187-activated platelets, but not thrombin- or ADP-activated platelets, induced EET formation in eosinophils.
• The induction of EETs was dose-dependent on the number of activated platelets.
• Platelet-induced EET formation was NOX-independent and sensitive to necroptosis inhibitors, unlike direct eosinophil stimulation.

Conclusions:

• Activated platelets and their products can induce EET formation in eosinophils.
• This platelet-mediated induction of EETs may enhance their role in eosinophilic airway inflammation.
• The findings suggest a novel pathway involving platelet-derived factors and necroptosis in allergic airway pathology.