The Effects Of Costimulatory Molecule CD137 On The Pathogenesis Of Asthmatic Pneumonia In Children

Objective To investigate the expression and significances of costimulatory molecules CD137,CD28,T lymphocyte and its subsets in peripheral blood of patients with bronchiolitis.To investigate changes and significances of cytokine IL-6,TNF -αin plasma of patients with bronchiolitis.Method Applying flow cytometry(FCM) and enzyme linked immunosorbent assay(ELISA) to quantitatively analyze CD137,CD28,T lymphocyte and its subsets,cytokine IL-6,TNF -αin patients with bronchiolitis and normal controls. Relation between costimulatory molecules CD137 and CD4~+,CD8~+ T lymphocyte IL-6,TNF -αwere also analyzed.Results FCM: The expression of costimulatory molecules CD137:There was no expression of CD137 on inactive T lymphocyte in normal controls,after stimulating by PHA for 24 hours,the expression was (19.67±2.00)%.There were expression of CD137 on inactive T lymphocyte already in patients with bronchiolitis, after stimulating by PHA for 24 hours ,the expression of CD137 is (34.67±3.65)%, more higher than the normal controls(P<0.01).In addition, we found there were expression of CD137 on both CD4~+ and CD8~+ T lymphocyte, and the expression on CD4~+ T lymphocyte were more higher than that on CD8~+ T lymphocyte. And the expression of CD137 on T lymphocyte in patients with bronchiolitis was significant different from the normal controls. The expression of costimulatory molecules CD28:There was no significant different between patients with bronchiolitis and the normal controls on the expression of costimulatory molecules CD28(P>0.05). T lymphocyte and its subsets showed that CD8~+CD28~+ in patients with bronchiolitis was more higher than the normal controls(P<0.01), CD8~+CD28-,CD4~+CD28~+ was more lower (P<0.05).and there was no significant different on CD4~+CD28- between them. In patients with bronchiolitis, the expression of CD137 on the allergen positives are significant higher than the negatives(P<0.05),but there was no statistastical different on T lymphocyte subsets between them.The expression of CD137 on MP infection and RSV infection was statistical different in patients with bronchiolitis in comparison with controls(P<0.05). But between them there was no significant different. Relation with T lymphocyte: there was negative correlation between expression of CD137 and CD4~+ T lymphocyte(r=-0.74, P<0.01), and positive correlation between expression of CD137 and CD8~+ T lymphocyte(r=0.82,P<0.01). Elisa: The expression of IL-6,TNF-αin plasma of patients with bronchiolitis were more higher than the normal controls.There were positive correlation between expression of IL-6 and expression of CD137(r=0.49,P <0.01). There were also positive correlation between expression of TNF-αand expression of CD137( r=0.55, P<0.01). And expression of IL-6 has no significant correlation with expression of TNF-α(r=0.21,P >0.05).Conclusion The costimulatory molecule CD137 play a critical role in the pathogenesis of bronchiolitis. Blocking the costimulatory pathway appears to be a promising approach of the prevention and therapy of bronchiolitis.