Staphylococcus aureus enterotoxin B facilitates allergic sensitization in experimental asthma

Area of Science:

• Immunology
• Allergy Research
• Microbial Toxin Research

Background:

• Staphylococcus aureus Enterotoxin B (SEB) exhibits immunomodulatory properties relevant to allergic airway diseases.
• The specific role of SEB in allergen sensitization remains largely uncharacterized.

Purpose of the Study:

• To investigate the impact of staphylococcal toxins on ovalbumin (OVA)-induced sensitization and allergic airway inflammation.
• To assess the combined effects of OVA nasal application with various toxins, including SEB.

Main Methods:

• Mice received alternate-day nasal applications of OVA with or without SEA, SEB, TSST-1, protein A, or LPS from day 0 to 12.
• On day 14, OVA-specific IgE, cytokine production (IL-4, IL-5, IL-10, IL-13) by mediastinal lymph node (MLN) cells, and bronchial hyperreactivity (BHR) were assessed.
• The influence of SEB on dendritic cell (DC) migration and maturation, and T cell proliferation was evaluated.

Main Results:

• Concomitant OVA and SEB administration led to significant OVA-specific IgE production, unlike other tested toxins or OVA alone.
• OVA/SEB mice exhibited enhanced DC maturation and migration to draining lymph nodes, alongside increased T cell proliferation.
• Bronchial inflammation, eosinophil and lymphocyte influx, hyperresponsiveness, and elevated IL-4, IL-5, IL-10, and IL-13 levels were observed in OVA/SEB mice.

Conclusions:

• SEB significantly facilitates sensitization to OVA, leading to allergic airway inflammation characteristic of asthma.
• This SEB-induced effect is attributed to augmented DC migration and maturation, and enhanced allergen-specific T cell proliferation.