Effects of Nasal Instillation of Staphylococcal Enterotoxin B on Nasal and Bronchial Mucosa in BALB/c Mouse

BACKGROUND AND OBJECTIVES: The effect of nasal exposure to staphylococcal enterotoxin in the pathogenesis of allergic rhinitis remains controversial. We sought to determine the effect of increasing doses of intranasally applied Staphylococcus aureus enterotoxin B (SEB) on the respiratory mucosa, especially the nasal mucosa. MATERIALS AND METHODS: Nasal application of SEB was performed on four occasions (days 0-4-8-12) in unsensitized BALB/c mice. Control mice were intranasally treated with phosphate buffered saline (PBS), and 5 ng, 50 ng, 500 ng, and 5 microg of SEB was applied to the respective experimental group. The concentrations of IL-4, IL-5, and IFN-gamma in bronchoalveolar lavage fluid (BALF), nasal lavage fluid (NLF) and serum were compared among groups. Also, the counts of total inflammatory cells, macrophages, lymphocytes, neutrophils, eosinophils, and basophils in BALF and NLF were compared among the groups. Pathologic studies for inflammatory cell infiltration in the nasal mucosa and peribronchial area were conducted. RESULTS: IL-4 and IFN-gamma showed higher concentrations with increasing stimulation dose of SEB in NLF and serum. The IL-5 concentration showed a tendency to increase in NLF and serum, but these changes were not statistically significant. Total inflammatory cell count, especially macrophage count, in BALF and NLF was higher with increasing stimulation dose of SEB. Infiltration of inflammatory cells into the nasal mucosa showed a tendency to increase in a dose-dependent manner. CONCLUSION: These results suggest that nasal exposure to SEB may induce Th1 and Th2 inflammatory responses in the respiratory mucosa, especially the nasal mucosa.

Role of Staphylococcus Aureus Exotoxins in Chronic Rhinosinusitis with Nasal Polyp / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Staphylococcal exotoxins (SEs) have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyp (CRSwNP). In the current study, we determined the prevalence of specific immunoglobulin E (IgE) antibodies to SEs in serum and polyp tissues of patients with CRSwNP and tried to find out whether there is an association between the presence of SEs-IgE antibody and eosinophilic inflammation. SUBJECTS AND METHOD: Blood, nasal polyp and mucosa samples were obtained from 43 patients undergoing endoscopic sinus surgery for CRSwNP and 11 controls undergoing septoplasty without CRS. Specimens were analyzed for the presence of specific IgE antibody to four SEs [staphylococcal enterotoxin A (SEA), staphylococcal enterotoxin B (SEB), staphylococcal enterotoxin C (SEC), toxic shock syndrome toxin 1 (TSST-1)] using ImmunoCAP assay. Eosinophil cationic protein (ECP) in serum and nasal polyp tissue were also analyzed using ImmunoCAP. Eosinophil counts were estimated in polyp tissue. RESULTS: SEs-specific IgE antibodies were detected in 13 (30.2%) patients of the CRSwNP group. In contrast, only one (9.1%) control patient had IgE to SEs. Serum ECP level was increased significantly in the CRSwNP group compared with controls. However, there were no significant differences in Lund-MacKay score, the ECP level in the serum and polyp tissue, and eosinophil count in the polyp tissue between the SEs-IgE antibody positive [SEs-IgE Ab (+)] group and the SEs-IgE antibody negative [SEs-IgE Ab (-)] group. CONCLUSION: SEs may play a certain role in the pathogenesis of CRSwNP. However, there is no close correlation between the presence of SEs-IgE antibody and eosinophilic inflammation.