[Expression and clinical significance of miR-155 in peripheral blood CD4(+);T cells of patients with allergic asthma].

Abstract

AIM: To investigate the expression and clinical significance of miR-155 in the peripheral blood CD4(+);T cells of patients with allergic asthma. METHODS: The expression of pre-mature BIC transcript and its processed microRNA miR-155 in the CD4(+); T cells from 50 patients with allergic asthma and 20 healthy individuals were measured using real-time PCR. The correlation of miR-155 expression and the disease severity of asthma was analyzed. The ability of miR-155 to influence Th1/Th2 differentiation was examined in vitro. RESULTS: The expression of pre-mature BIC and miR-155 in the CD4(+); T cells of asthma patients significantly decreased compared to those in normal controls (P<0.01). Furthermore, the expression of BIC in moderate and severe asthma patients was lower than that in normal controls (P<0.05). Among mild, moderate, severe asthma patients, BIC expression showed no statistical significance, but miR-155 expression of severe asthma patients was lower than that in mild asthma patients (P<0.05). The expression level of miR-155 was positively correlated to FEV1/pred(%) (P<0.01). miR-155 over-expression was found to promote CD4(+); T cells to Th1 differentiation, while of miR-155 was found to induce CD4(+); T cells to Th2 differentiation. CONCLUSION: The decreased expression level of miR-155 is correlated to asthma disease severity. It is suggested miR-155 plays an important role in development of asthma.