Staphylococcus aureus proteases trigger eosinophil-mediated skin inflammation.

Area of Science:

• Immunology
• Dermatology
• Microbiology

Background:

• Staphylococcus aureus colonization and eosinophil infiltration are linked to inflammatory skin conditions like atopic dermatitis.
• The precise relationship between S. aureus and eosinophils in skin inflammation remains unclear.

Purpose of the Study:

• To investigate the role of S. aureus in eosinophil recruitment and activation in skin inflammation.
• To elucidate the mechanisms by which S. aureus drives eosinophil-mediated inflammatory responses in the skin.

Main Methods:

• Utilized a preclinical mouse model of S. aureus epicutaneous exposure.
• Analyzed chemokine production, eosinophil infiltration, and cytokine profiles (IL-17A, IL-17F, IL-36α).
• Investigated the role of IL-36R signaling and S. aureus proteases in eosinophil recruitment.

Main Results:

• S. aureus exposure induced eosinophil-recruiting chemokines and skin infiltration.
• Eosinophils contributed significantly to skin inflammation, dependent on IL-17A and IL-17F.
• IL-36R signaling promoted eosinophil recruitment via CCL7; S. aureus proteases induced IL-36α, driving IL-17-producing eosinophil infiltration.

Conclusions:

• S. aureus proteases activate a pathway involving IL-36α and CCL7 to recruit IL-17-producing eosinophils.
• This mechanism highlights eosinophils as key players in S. aureus-induced skin inflammation.
• Findings offer insights into the pathogenesis of inflammatory skin diseases involving S. aureus and eosinophils.