The Role And Mechanism Of TLR2 In An Experimental Asthmatic Mice Model

PART Ⅰ Role of TLR2 in the Mice Model of Asthma【Objective】To investigate the role of TLR2 in asthmatic mice.【Methods.】The experiment was divided into three groups: TLR2-/- asthma group、C57BL/6 asthma group and control group, 8 mice in each group. Mice were sensitized and challenged with OVA as asthmatic mice models. Alveolar ravage fluid was collected, centrifuged and separated; part side of the lung tissue was stained with HE, the pathological changes of lung tissue were observed by HE stain; IL-4, IL-5, IL-13 m RNA expression were detected by RT-PCR method.【Results】In the TLR2-/- group, the degree of inflammatory cells around the vascular tissue was reduced, compared with C57BL/6 group(P <0.05). No airway epithelial cell shedding. The amount of eosisnophils, lymphocytes in BALF was significantly reduced in TLR2-/- group,while the amount of macrophages was increased significantly, compared with C57BL/6 group(P <0.05).Compared with control group, the number of eosinophils and lymphocytes were significantly increased in the C57BL/6 group, while the amount of macrophages were decreased(P <0.05). Compared with C57BL/6 group, IL-4, IL-5 and IL-13 m RNA expression in the TLR2-/- group were decreased significantly(P <0.05),but increased compared with control group(P <0.05).【Conclusion】TLR2 may participate in pathogenesis of asthma, allergic asthma is dependent partly on TLR2.PART Ⅱ Experimental Study of TLR2 in the Signal TransductionPathway in a Mice Model of Asthma【Objective】To investigate the possible signal transduction pathway of TLR2.【Methods】The experiment was divided into three groups: TLR2-/- group, C57BL/6 asthma group and control group, 8 mice in each group. Mice were sensitized and challenged with OVA as asthmatic mice models. The expression of Akt, p 38, ERK, NF- B kappa p65 protein and phosphorylation of Akt, p38, ERK in lung tissue were detected by immunohistochemistry(Envision two steps).【Results】In the control group,only non phosphorylated ERK was detected in lung tissue. Akt, p38, NF- kappa B p65 and phosphorylation of Akt, ERK, p38 in lung tissue of TLR2-/- mice were reduced, compared with C57BL/6 group(P <0.05).【Conclusion】Deficiency of TLR2 attenuates allergic airway inflammation and it is mediated through inhibition of the Akt and ERK signaling pathway.PART Ⅲ The Establish of Lung APC Subsets in TLR2-/- AsthmaticMice【Objective】To study the expression of APC in lung tissue of TLR2-/- asthmatic mice.【Methods】The experiment was divided into four groups: TLR2-/- asthma group, TLR2-/- control group, C57BL/6 asthma group and C57BL/6 control group, 8 mice in each group. Mice were sensitized and challenged with OVA as asthmatic mice models. The expression of CD103+DCs, CD11b+DCS, p DCs, alveolar macrophages and interstitial macrophages cell subsets in lung tissue were detected by flow cytometry.【Results】The level of interstitial macrophages was increased significantly in TLR2-/- asthmatic group, compared with C57BL/6 group(P <0.05).【Conclusion】Deletion of TLR2 attenuates allergic airway inflammation and it is mediated through the protective effect of interstitial macrophages.PART Ⅳ IL-33 and IL-4 in Serum of Asthmatics and CorrelationAnalysis【Objective】To investigate the expression and correlation between IL-33 and IL-4 in children with asthma.【Methods】Three groups:22 children with acute attack of asthma, 20 children with wheezing and 18 children with inguinal hernia. The levels of IL-33, IL-4 in serum were detected by ELISA.【Results】In asthma group, the levels of IL-33 protein was increased significantly, compared with wheezing group and normal group(P < 0.05); IL-4 protein level in serum was increased in asthma group,compared with wheezing group and normal group(P < 0.05). There was a positive correlation(r = 0.578, P < 0.05) between IL-33 and IL-4.【Conclusion】The level of IL-33 was increased during acute attack of asthma and can promote the IL-4 level, so as to promote the development of airway inflammation in asthma.