Change From The T Cell Receptor ¦Ä Chain Polymorphism And T Cell Apoptosis Of Bronchial Asthma, Chronic Airway Inflammation Mechanism

Objective:Via detecting the proportion of γδT cells, the expression and the clonality of V5 subfamilies in the peripheral blood(PB) and bronchoalveolar fluid (BALF) of asthmatic subjects to set a better understanding of the role of y8T cells in the asthmatic airway inflammation and identify the forces which induce and maintain the inflammatory process.Methods:Peripheral blood(PB) and BALF were obtained from seven mild to moderate symptomatic asthmatic subjects, eight nonsmoking control subjects which consisted of two patients with occasional blood stained sputum, four with peripheral lung cancer in early stage, one with bronchial stenosis due to the old endothelial tuberculosis and one with chronic cough caused by gastro-esophageal reflux disease. The experimental methods were used as follows: (1) The total cells of BALF were counted and differentiated in cytospin preparations and HE stain; (2) The percentage of CD₄⁺T cells, CD₈⁺T cells and γδT cells in PB and BALF were measured by immunofluorescent staining and flow cytometry; (3) The analysis for expression of the three V8 subfamilies in PB and BALF was performed by reverse transcriptase - polymerase chain reaction(RT-PCR), the frequency of usage and the clonality of each V8 subfamily were assessed by gene scanning; (4) Monoclonal V8 subfamily were selected and their PCR products were subcloned and sequenced to characterize fully the sequence diversity.Results:1. Direct bronchoscopy revealed moderate to severe diffusive congestion on bronchial mucus in all asthmatics. The asthmatic subjects had significantly higher percentage of eosinophils and lymphocytes in BALF than control subjects. The distribution of CD₄⁺ and CD₈⁺ T subsets in PB and BALF had no difference between both groups,...