Anti-IL-5 immunomodulates the effect of Staphylococcus aureus enterotoxin on T cell response in nasal polyps

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a T helper-2 (Th2) inflammatory disease with considerable impact on the quality of life. Staphylococcus aureus enterotoxins (SAEs) can induce and/or amplify inflammation. In this study, we investigated the immunomodulatory effect of SAEs on cytokine production by T cell obtained from nasal polyps (NPs) and examined whether neutralizing interleukin 5 (IL-5) can reverse the immunological effect mediated by those toxins. Methods: NP tissues were obtained from all patients who underwent endoscopic sinus surgery for CRSwNP. NP cells were isolated and stimulated in vitro with SAEs in the presence or absence of anti-IL-5. Flow cytometry (FACS) analyses were performed to measure specific T lymphocyte cytokine production. Results: Seventeen patients (mean age 48 years) were enrolled. SAEs significantly increased the IL-4, IL-5 (Th2) and interferon (INF)-γ (Th1) cytokines released from T lymphocytes of NPs. The addition of anti-IL-5 suppressed IL-4 and INF-γ release, which was most evident on NP tissue with high basal levels of IL-5. Conclusions: Neutralizing IL-5 is a potential therapeutic modality in patients with NPs, the effect of which is dependent on IL-5 levels.