The Impact of IL-18 on the Differentiation of CD4+ Th2 and Th17 Cells and the Expression Levels of IL-18Rα in Lung Tissues of Mice with Allergic Asthma

Objective To investigate the effect of interleukin 18 (IL-18) on the differentiation of CD4 helper cell 2 (Th2) and T helper cell (Th17) and the level of IL-18 receptor α α (IL-18Rα) expressed in lung tissues of mice with allergic asthma (AM).Methods Healthy mice (HM) and AM alveolar lavage fluid (BALF) were collected and their lung tissues were prepared into single-cell suspensions, and the ratio of CD4 Th2 cells to Th17 cells and the expression level of IL-18Rα were detected by flow cytometry. Enzyme-linked immune sorbent assay (ELISA) was used to detect the levels of cytokines IL-4 and IL-17A in BALF.Results Compared with HM, the proportions of CD4 Th2 cells and Th17 cells in AM lung tissue were significantly increased, and the expression level of IL-18Rα in CD4 Th2 cells was increased (P<0.05), while the expression level of IL-18α in Th17 cells was not statistically different, and IL-4 and IL-17A in AM BALF were significantly higher than those in HM group, and this difference was correlated with the proportion of Th2 and Th17 cells.Conclusion IL-18 may be involved in the pathogenesis of allergic asthma by inducing the differentiation of CD4 T cells into Th2 cells and Th17 cells, and up-regulating the expression of IL-18Rα in Th2 cells in lung tissue of asthma mice.