A Stuty On The Diversification Of Interleukin-17 Of Asthma Mouse And The Affection Of The Treament Of Glucocorticoids

Objective:Estabilishment of the KUNMING mouse model by OVA and the observation of the change of the cell classification in BALF, the change of pathology of the mouse, and IL-17, IgE in the serum of mouse.To investigate the mechanisms of IL-17 in the pathogenesis of asthma and the affection of glucocorticoids for asthma.Methods:SPF female KUNMING mice (4 to 6 weeks),18-20 g, were purchased from Laboratory Animal Services Center of Dalian Medical University. Thirty mice were randomly divided into 3 groups: asthmatic group (A),budesonide group (B) and normal group (C). Each group has 10 mice. For establishing the mouse asthma model, the mice of A and B group were first sensitized to OVA (OVA 20μg+150μL Al(OH)3+50μL NS) via intra-peritoneal injection on days 0 (the day on the beginning of the experiment), day 7 and day 14. On the day 28, 29 and 30, those mice (A and B) were firstly challenged with OVA-NS intranasally, then were re-challenged with 2% OVA in saline aerosol by an ultrasonic nebulizer for 30 min every day from day 30 to 60. But the treatment of budesonide group (B) is different from asthmatic group (A) from day 30 to 60. The mice of budesonide group were treated with budesonide intranasally before the atomization. The normal mice received saline alone under the same conditions without sensitization and re-challenge of OVA. The animals were killed by cervical dislocation 24 h after the last exposure to aerosol re-challenge. And we collected blood by eye extraction.Then mice were subjected to bronchoalveolar lavage. The bronchoalveolar lavages were stained with HE and eosinophil number counted with a hematocytometer. At least 400 lymphocytes were counted by microscopy before the percentages of EOS cells were calculted. After bronchoalveolar lavage, the animals were sacrificed their lungs harvested and fixed in 10% phosphate buffered formalin. Tissues were sliced and HE stained for histological examination, including morphology, epithelial injury, perivascular and peritracheal infiltration of eosinophils. The blood that we collect was offcentered 3000 r/min for 5 min. We kept some serum in -80℃for IL-17A. The other serum was kept in 4℃for IgE. IL-17A,IgE in serum was determined by sandwich enzyme-linked immunosorbent assay (ELISA).Results:1.The behavior changes after re-challenge. Mice in asthmatic group displayed various types of allergic responses, such as scratching head and face, dyspnea, oral lip cyanosis, muscle spasm as well as gatism, while control group showed no such symptoms. Mice in budesonide group (B) also showed no such symptoms.2.Histological analysis. Massive leukocyte infiltration was present in the lungs from the asthmatic mice. Neutrophils, eosinophils and lymphocytes were mainly found in the alveolar, interstitial and peribronchial regions. Goblet cell hypertrophy, epithelial damage, mucus hypersecretion, mucus plugs, as well as collagen deposition were also easily identified. While lungs in the control and budesonide mice showed a clear airway structure without inflammatory cell infiltration or collagen deposition.3.The percentage of eosinophils in BALF. The percentages of BALF eosinophils in the asthmaticis group 15.503士1.235%, that is also significantly higher than that in the control group 1.892士1.029% and budesonide group 4.628士1.440% (P <0.01 ).4.The level of IL-17A in serum. IL-17A in serumwas much higher in the asthmatic mice (10.714士2.287 ng/ml)than that in the normal control group(0.3860士0.1456 ng/ml) and budesonide group(5.807士1.653 ng/ml) (P<0.01 ).5.The level of IgE in serum. IgE of the asthmatic micein serum (6.939士0.119 ng/ml ) was much higher than that of the normal control group (5.443士0.249 ng/ml ) and budesonide group (5.538士0.240 ng/ml ) (P<0.01 ). There is no difference between the normal control group and budesonide group (P>0.05 ).6.In the asthmatic mice, IL-17 in serum was positively correlated with the IgE in serum and the percentages of eosinophils.( r=0.720,P=0.019; r=0.892,P=0.001)Conclusion:(1)The mouse asthma model was established by intra-peritoneal injection OVA.(2)Inflammation cells agglomeration happens due to IL-17A. IL-17A can make inflammatory cell infiltration in the lung.(3)Glucocorticoids can inhibit the production of IL-17 and make fewer inflammatory cell infiltration.