Allergen induced Th17 response in the peripheral blood mononuclear cells (PBMCs) of patients with nasal polyposis.

BACKGROUND: Nasal polyposis (NP) is a chronic inflammatory disease of the nasal cavity and sinuses. Th17 cells have been considered to play roles in allergic airway diseases and various chronic inflammatory disorders.

AIM OF THE STUDY: This study aimed to investigate the population and function of peripheral Th17 cells in response to house dust mite extracts (HDM) allergen in NP patients, and evaluate the possible correlation between Th17 cells and atopy, to explore the role of atopy in the pathogenesis of NP.

METHODS: Peripheral blood mononuclear cells (PBMCs) obtained from atopic NP patients, non-atopic NP patients, and controls were stimulated by phytohemagglutinin (PHA) or HDM plus PHA. The resulting frequency of Th17 cells was detected by flow cytometry and the expression of RORc was measured by real-time PCR. Then the concentrations of IL-17A, INF-γ, IL-4 and IL-5 in the supernatants were assayed by specific ELISAs.

RESULTS: The population and function of Th17 cells in allergen stimulated PBMCs were significantly higher in atopic NP patients. In addition, in atopic group, HDM+PHA stimulation induced significant increase of Th17 population and IL-17A production versus those in PHA stimulated ones. However, the frequency of Th17 cells was not correlated with Th1, Th2 cytokine productions.

CONCLUSION: Th17 immunity is involved in the systemic immune responses to allergen in atopic NP and atopy may aggravate NP by stimulating the increase of Th17 population and IL-17A production. The mechanism of Th17 cells response to allergen may be regulated differently from the regulation of Th1 and Th2 immunity in NP.