Cooperation Between Th1-type And Th2-type Cells In Asthmatic Airway Inflammation

Objective T lymphocytes play an important role in the development of chronic airway inflammation in patients with bronchial asthma By observing the production of IFN- γ and IL-4 released by peripheral T lymphocytes in asthmatic patients and rat models, this study was designed to clarify the dynamic changes of proliferation and differentiation of T lymphocytes during the course of airway inflammation, as well as the relationship between these changes and airway inflammation. The influence of dexamethasone pre-treatment on the production of IFN-γ and IL-4 by T lymphocytes were also investigated at the same time in rat models. Our study would be expected to provide some laboratory evidence and theoretical basis for the treatment of bronchial asthma in future.Methods Twenty patients with mild to moderate acute episode and 15 patients with remission of asthma were included in this study. Eleven normal subjects were also enrolled as control group. Blood samples were collected and the percentage of IFN- γ +CD4+, IFN- γ +CD8+ and IL-4+CD4+ cells were determined by flow cytometry method. Asthmatic rat models were established in the study. Rats were sensitized and challenged by ovalbumin(OVA), blood samples were taken and the percentage of IFN- γ +CD4+, IFN-γ+CD8+ and IL-4+CD4+ cells were assessed at 2hr, 4hr, 6hr, 8hr, 10hr,12hr, 24hr, 36hr, 48hr, 72hr, 6d, 9d, 12d, 15d, with flow cytometry after OVA challenge . And the pathologic changes of airway inflammation were observed with the animal models killed at different time points after OVA challenge. The other group of rats were treated intraperitoneal injection with dexamethasone (10mg/kg) before OVA inspiration. The influence of dexamethasone on the production of cytokines were observed and the production of cytokines were compared among different groups of rats. Results1) Peripheral IFN-γ+CD4+, IFN-γ +CD8 and IL-4+CD4+cells were higher in patients with acute episode asthma (30.10±10.49%, 42.48±15.2%, 4.21±1.57%, respectively) than those in patients with remission asthma (20.04±7.65%, p<0.01;...