Analysis of the levels of Th9 cells and cytokines in the peripheral blood of mice with bronchial asthma

The purpose of the study was to detect the level of T-helper type 9 (Th9) cells and the cytokine interleukin-9 (IL-9) in peripheral blood of mice with bronchial asthma, and to explore the relationship between the expression of Th9 cells and the pathogenesis of asthma. Thirty female-specific pathogen-free (SPF) Bagg' albino (BALB)/c mice were selected and randomly divided into the control group (n=15) and the bronchial observation group (n=15). Mice in the bronchial observation group were treated with ovalbumin (OVA) for sensitization and induction of a mouse model of asthma. The airway reactivity of mice was measured by a mouse pulmonary function apparatus using the non-invasive pulmonary impedance method. The proportions of Th9 cells in peripheral blood of mice in the two groups were detected using flow cytometry. Digital polymerase chain reaction (dPCR), enzyme-linked immunosorbent assay (ELISA) and western blot analysis were applied to detect the levels of IL-9 messenger ribonucleic acid (mRNA) and proteins in peripheral blood and lung tissues of mice in the two groups, respectively. Compared with that in the control group, the expression level of Th9 cells in the peripheral blood of mice in the observation group was significantly elevated (P<0.05), the expression level of IL-9 proteins in the peripheral blood was significantly increased (P<0.05), and the levels of IL-9 mRNA and proteins in lung tissues were significantly increased (P<0.05). The results show that the levels of Th9 cells and their cytokine IL-9 in the peripheral blood of mice with bronchial asthma are significantly increased, suggesting that Th9 cells play important roles in the pathogenesis of asthma.