Clinical Research On PI3K Signal Transduction Pathway Palying A Role In Th1／Th2 Response Imbalance Of Asthmatic PBMC

Objective:To observe phosphoinositide 3-kinase(PI3K) activity in peripheral blood mononuclear cell(PBMC) in patients with acute asthma,To observe meanwhile Wortmannin(one of specific inhibitor of PI3K)effect on expression of IFN-γ(Th1 cytokine) and IL-4(Th2 cytokine) in supernatant of cultured PBMC. to analyze potential contribution of PI3K signal transduction pathway to Th1/Th2 response imbalance in the T lymphocyte immunologic derangement of asthma. Method:20 patients with acute asthma and 15 normal controls were selected for this study. PBMC were obtained with Ficoll density gradient centrifugation,the expression of PI3K gene in PBMC was detected by RT-PCR,ELISA was used to measure IFN-γand IL-4 in supernatant of cultured PBMC interfered by Wortmannin with various concentration gradient. Results:The expression of PI3K gene in PBMC in patients with acute asthma were higher than those in the controls(P<0.05).Comparing with the control group,the expression of IFN-γwas significantly lower and the expression of IL-4 was significantly higher in supernatant of cultured PBMC from asthmatic patients(P<0.01 and P<0.01).After the culture with Wortmannin in various concentration gradient, the expression of IL-4 was significantly decreased in a dose-dependent manner in asthmatic patients and normal controls(P<0.05 or P<0.01), but the expression of IFN-γwas no difference(no statistical significance). Conclusion:The overactivity of PI3K signal transduction pathway possibly involves in patients with acute asthma. PI3K possibly play a important role in Th1/Th2 response imbalance of asthma by regulating the production of IL-4 but not IFN-γ.