Eosinophils: old cells, new directions

Area of Science:

• Immunology
• Cell Biology

Background:

• Eosinophils are polymorphonuclear cells involved in diseases like asthma and parasitic infections.
• Recent research highlights their roles in homeostatic processes and various eosinophilic disorders.
• Biological therapies targeting eosinophils are emerging for eosinophilic pathologies.

Purpose of the Study:

• To comprehensively analyze eosinophils based on recent findings.
• To explore the division of eosinophils into distinct functional populations.
• To review the emerging theory of resident (rEos) and inflammatory (iEos) eosinophils.

Main Methods:

• Review of recent scientific literature.
• Analysis of studies on eosinophil protein expression patterns.
• Examination of eosinophil localization in murine models and human tissues.

Main Results:

• Evidence supports the existence of distinct eosinophil subtypes.
• Differences in protein expression and localization define these subtypes.
• The proposed classification includes resident eosinophils (rEos) and inflammatory eosinophils (iEos).

Conclusions:

• Eosinophils comprise at least two functionally distinct populations.
• This classification offers new insights into eosinophil roles in health and disease.
• Further research is warranted to fully elucidate the functions of rEos and iEos.