Staphylococcus aureus enterotoxin B disrupts nasal epithelial barrier integrity

Area of Science:

• Immunology
• Cell Biology
• Otorhinolaryngology

Background:

• Staphylococcus aureus colonization and enterotoxin B (SEB) are linked to severe chronic rhinosinusitis with nasal polyps (CRSwNP).
• The pathogenic mechanisms of SEB on epithelial barriers remain largely unexplored.

Purpose of the Study:

• To investigate the effect of SEB on nasal epithelial barrier function in CRSwNP.

Main Methods:

• Apical administration of SEB to air-liquid interface (ALI) cultures of primary nasal polyp epithelial cells and healthy controls.
• Evaluation of epithelial cell integrity and tight junction expression.
• In vitro and in vivo studies using Toll-like receptor 2 (TLR2) antagonism and tlr2 knockout mice.

Main Results:

• SEB decreased epithelial cell integrity and tight junction protein expression (occludin, ZO-1) in polyp cells.
• TLR2 antagonism prevented SEB-induced barrier disruption.
• SEB increased mucosal permeability and decreased occludin/ZO-1 mRNA in control mice, but not in tlr2 knockout mice.
• SEB induced IL-6 and IL-8 production, which was blocked by TLR2 antagonism.

Conclusions:

• SEB damages nasal polyp epithelial cell integrity by triggering TLR2 in CRSwNP.
• SEB may drive disease exacerbation rather than cause primary epithelial defects in CRSwNP.
• Interfering with TLR2 may mitigate S. aureus-induced inflammation in CRSwNP.