Effects Of Soluble Interleukin5Receptor α Combined Soluble Interleukin13Receptor α2on IgE, IFN-γ, VCAM-1, And STAT6Levels In Asthmatic Animal

Asthma is a complex disease which the main features are airwayhyperresponsiveness, reversible airflow limitation, airway inflammation, andvarying degrees of subepithelial fibrosis, mucus hypersecretion and airwayremodeling, but the pathogenesis is still not very clear. Studys found that theTh1/Th2imbalance was one of the main pathogenesis of asthma. CD4+T cellsare divided into two subsets, such as Th1subset and Th2subset, Th1cellssecrete IFN-γ, which mediat cellular immunity, can be a negative regulator ofTh2response, inhibit the development of lung allergic inflammation. Th2cells mainly produce IL-4, IL-5and IL-13which mediate immune and allergicdiseases. Studys confirmed that the increased expression of Th2cells wereclosely related to asthma, and the increased expression of Th2cells have beenconfirmed in asthmatic animal, asthma patients’ serum and bronchoalveolarlavage fluid and tracheal biopsy. IL-5can activate a series of eosinophils (EOS) reaction, combined with the EOS receptor; IL-5play an important rolein the regulation of EOS differentiation, aggregation, activity, and extend thematurity EOS lifetime, IL-5also can promote B cell differentiation andproliferation, enhance the ability of IL-4to promote B-cell synthesis andsecret IgE, promote the aggregation and activation of basophils, increasemucus secretion, airway fibrosis and airway remodeling. IL-13can adjust theactivity of IgE, mast cells and eosinophils, and mediate airwayhyperresponsiveness and mucus hypersecretion, IL-13play an important rolein the pathogenesis of asthma. Soluble IL-5receptor alpha (sIL-5Rα) can becombined with IL-5, suppress the IL-5-induced signal transduction and thedilivery of regulatory cytokines, and inhibit the differentiation ofallergen-induced EOS, play the role of immunoloregulation. IL-13receptor α2(IL-13Rα2) have a high affinity with IL-13, and as a decoy receptor whichcould inhibite IL-13signal transduction and response. There are three formsof IL-13Rα2, membrane proteins, intracellular proteins and soluble proteins,the soluble IL-13Rα2(sIL-13Rα2) play an important role. sIL-13Rα2cansignificantly reduce allergen-induced airway hyperresponsiveness andinflammation. The excess IL-13Rα2in bronchus can reduce IL-13-associatedSTAT6phosphorylation. Studys found that IL-5, IL-13could mediated IgE,VCAM-1, STAT6, and led to vascular permeability changes, inflammatorycell proliferation, migration, infiltration and so on, in the end, arrivaling theasthma symptoms coughing, wheezing, and AHR. So far we don’t read therelevant literature of the effects of the combination of sIL-5Rα and sIL-13Rα2on IgE, IFN-γ, VCAM-1and STAT6level in asthmatic animal. In this study,we investigate the effects of sIL-5Rα and sIL-13Rα2on IgE, IFN-γ, VCAM-1and STAT6level in asthmatic animal, to look for new method to cure asthma. Objective:1. Observing the effects of the combination of sIL-5Rα and sIL-13Rα2on IgE, IFN-γ levels in asthmatic animal, to understand the Th1/Th2imbalance of asthma pathogenesis and seek a new treatment ways to asthma.2. Observing the effects of the combination of sIL-5Rα and sIL-13Rα2on VCAM-1, STAT6levels in asthmatic animal, to further explore the roles ofIL-5and IL-13in the pathogenesis of asthma, and to understand the value ofthe combination of sIL-5Rα and sIL-13Rα2to cure asthma.Methods:1. A total of100BALB/c mice were randomly divided two parts,50BALB/c mice in each one part, the one part for the first part of the experimentand another part for the second part of the experiment. Each one part of micewere randomly divided the normal group, the asthmatic group, the sIL-5Rαtreatment group, the sIL-13Rα2treatment group, the combination of sIL-5Rαand sIL-13Rα2treatment group (short for the combined treatment group).Mice in the latter4groups were sensitized with ovalbumin (OVA) andAL(OH)3, and challenged with OVA to establish asthmatic models, whilemice in the normal group were treated with saline. Mice in the sIL-5Rαtreatment group, the sIL-13Rα2treatment group and the combined treatmentgroup were injected intraperitoneally with sIL-5Rα (100μg), sIL-13Rα (100μg)and the combination of sIL-5Rα (100μg) and sIL-13Rα2(100μg)30minbefore challenged, while mice in control group and asthmatic group receivedsaline.2. The levels of IgE and IFN-γ of BALF and serum and the levels ofVCAM-1of serum were measured by ELISA.3. The levels of STAT6were measured by Immunohistochemical method and RT-PCR.Results:1.①compared with normal group, the IgE of BALF and serum inasthmatic group were significantly increased [(14.53±0.90) ng/mL vs(8.20±0.69) ng/mL and (1123.77±207.58) ng/mL vs (264.48±67.99) ng/mL],the IFN-γ were remarkably decreased [(107.96±6.63) pg/mL vs (371.4±32.92)pg/mL and (468.68±29.01) pg/mL vs (946.4±75.61) pg/mL](P<0.01).②compared with asthmatic group, the IgE of BALF and serum in the sIL-5Rαtreatment group, sIL-13Rα2treatment group, the combined treatment group[(12.42±0.40) ng/mL and (750.54±27.32) ng/mL,(12.49±0.38) ng/mL and(730.68±38.04) ng/mL,(10.82±2.17) ng/mL and (439.92±25.01) ng/mL] weresignificantly decreased (P<0.01); the IFN-γ [(197.92±24.30) pg/mL and(590.51±28.24) pg/mL,(196.2±18.27) pg/mL and (574.9±26.61) pg/mL,(343.9±33.51) pg/mL and (861.4±36.31) pg/mL] were significantly increased(P<0.01).③Compared with the single treatment group, in the combinedtreatment group the IgE were significantly decreased and IFN-γ weresignificantly increased (P<0.01).2.①In asthmatic group, the VACM-1of serum [(361.81±20.16) ng/mL]were remarkably higher than that in normal group [(203.56±22.26) ng/mL];compared with asthmatic group, the VCAM-1of serum in the sIL-5Rαtreatment group [(311.61±25.13) ng/mL], sIL-13Rα2treatment group[(306.33±23.63) ng/mL], the combined treatment group [(248.51±19.32)ng/mL] were significantly decreased (P<0.01); compared with singletreatment, the combined treatment group has more significantly differences(P<0.01).②Immunohistochemical mehtod and RT-PCR results showed that:compared with normal group, In asthmatic group STAT6of lung tissue was significantly increased (P<0.01); compared with the asthmatic group, STAT6of lung tissue in the sIL-13Rα2treatment group and combined treatmentgroup were significantly decreased (P<0.01), but the sIL-5Rα treatment grouphad no significantly changes (P>0.05); compared with sIL-13Rα2treatmentgroup, the combined treatment group also had significantly changes (P<0.01).Conclusion:The Combination of sIL-5Rα and sIL-13Rα2to treat asthmatic mousemodel, could significantly reduce the levels of IgE, VCAM-1and STAT6, andincrease the level of IFN-γ, which lead to reduce the lung tissue inflammation,airway remodeling and achieve the purpose of mitigation and treatment ofasthma, in the end, we can look for a new method to cure asthma.