[Upregulation of IL-18 expression in blood CD4+ Th2 cells of patients with allergic rhinitis].

ABSTRACT

Objective To investigate the expressions of IL-18, IL-18 binding protein isoform a (IL-18BPa) and IL-18 receptor α (IL-18Rα) in blood CD4+ Th2 cells of patients with allergic rhinitis (AR) and the effects of allergens on their expressions. Methods Blood samples of AR patients and healthy control subjects (HCs) were collected. Peripheral blood mononuclear cells (PBMCs) and CD4+ T cells sorted by immunomagnetic beads were stimulated by crude extract of Artemisia sieversiana wild allergen (ASWE), Platanus pollen (PPE) and house dust mite extract (HDME). Flow cytometry was used to detect the expression of IL-18, IL-18BPa and IL-18Rα in CD4+ Th2 cells, and BioPlex was used to detect the level of plasma IL-4 and analyze its correlation with the proportion of IL-18+ Th2 cells. Results Compared with HCs, the proportion of IL-18+ cells was increased in Th2 cells of AR patients; MFI of IL-18 was increased, while that of IL-18Rα was decreased. Moreover, allergens induced IL-18 and IL-18Rα expression in sorted CD4+ Th2 cells of HCs and induced IL-18Rα in that of AR patients. Additionally, elevated plasma IL-4 level was found in AR patients, which was moderately correlated with the percentage of IL-18+ Th2 cells. Conclusion Allergens may be involved in the pathogenesis of AR by inducing expression of IL-18 in peripheral blood CD4+ Th2 cells.