Response of Peripheral Blood Lymphocytes to Fungal Extracts and Staphylococcal Superantigen B in Chronic Rhinosinusitis

Abstract

Background: Previous studies have suggested that chronic rhinosinusitis may result from a hypersensitivity response of the nasal mucosa to the presence of fungal antigens or staphylococcal superantigens in the nasal mucus. Both of these groups of antigens are present so frequently in the nasal mucus of patients with chronic rhinosinusitis that their presence together is likely to be a common event. Objective: The objective of this study was to determine whether the combined presence of fungal antigens and staphylococcal superantigens exert a synergistic proinflammatory effect on peripheral blood lymphocytes from patients with chronic rhinosinusitis. Methods: Peripheral blood lymphocytes were extracted from patients with chronic rhinosinusitis with and without nasal polyposis (n = 7 for both groups) and normal controls (n = 7). These cells were cultured for 48 hours after the addition of fungal extracts (Aspergillus and Alternaria), staphylococcal superantigen type B (SEB), or a combination of these two antigens. Real-time polymerase chain reaction was used to determine the level transcription of interleukinL-5 and interferon-γ genes. Results: Fungal extracts alone resulted in minimal changes in the levels of cytokine expression in peripheral blood lymphocytes. SEB increased the expression of IFN-γ, and this effect was magnified by the addition of SEB and fungal extracts together to the culture medium. There were no differences in the magnitude of responses seen in patients with and without polyps nor between patients with chronic rhinosinusitis and normal controls. Conclusion: SEB exerts a powerful proinflammatory effect on peripheral blood lymphocytes and fungal extracts may act synergistically to promote this action.