Effects Of Combination Of Soluble Interleukin5Receptor And Interleukin4Mutant Airway Hyperresponsiveness And IgE、ifn-γLevels In Asthmatic Mice

Asthma is chronic airway inflammation involved a variety of cells and with the main characteristic of hyperresponsiveness and airway remodeling, eosinophil (EOS) is the key effect cells in asthma.The aggregation of pulmonary EOS has two mainly ways: IL-5dependent pathway and IL-5independent pathway, IL-5and IL-13respectively play a key role in this two ways. Clinical and experimental studies have confirmed that, CD4+Th2cells and the production of specific cells (especially IL-4, IL-5, IL-10, IL-13) play a critical role in airway hyperresponsiveness (AHR) induced by allergic inflammation. IL-4and IL-13are key factors of B cells IgE conversion, IL-4and IL-13up-regulate the expression of B cells and mononuclear cells low affinity IgE receptor (CD23, FceRII), enhance the expression of antigen and regulate the function of macrophages. As everyone knows, IL-5regulates the activation, proliferation, differentiation and survival time of eosinophil (EOS), plays an important role in allergic airway inflammation and airway hyperresponsiveness. IL-5plays an important role in EOS by binding to its receptors, IL-5binding and the effect on EOS through its receptor, IL-5receptor contains two subunit which are α and β, and forming membrane bound and soluble protein, soluble IL-5receptor (sIL-5R a) can block the role of IL-5cytokines in vitro, so as to achieve the purpose of inhibiting the gathering of EOS and has anti-inflammatory effect. There are a lot of IL-4mutant (IL-4MT) with blocking function, The double mutant (Q116D, Y119D),which the116glutamic acid and tyrosine at position119was replaced by aspartic acid. Type II IL-4receptor is comprised of IL-4receptor a (TL-4R α) and IL-13R α1, which is IL-13R. IL-4MT can bind to IL-4R and IL-13R, but does not cause signal transduction, which used as IL-4and IL-13blockers.Research considers, there are interactions between Thl and Th2, ratio imbalance of Thl and Th2cell is an important mechanism for the pathogenesis of asthma. Thl mainly mediates cellular immune responses, IFN-y is Thl type cytokine. Th2mediates humoral immune response,assist B cells to produce IgE.In normal body, ThO differentiate into Thl and Th2in accordance with a certain proportion. Research shows that the Thl/Th2ratio of patients with asthma tends to the dominance of Th2,the function of Th2cell rise abnormally. The relationship between Thl and Th2is the mutual inhibition, Thl type cytokines can offset the role of Th2type cytokine.The Changes of IFN-y and IgE levels can indirectly reflect the change trend between the ratio of Thl and Th2.Due to the complexity of the disease and the heterogeneity of asthmatic patients,it is difficult to play a role in all of the patients with asthma when we aim at a specific molecular target block, so the multifaceted intervention is the focus of our future research direction. In this study,we combined application of IL-5soluble receptor (sIL-5R a) and IL-4mutant (TL-4MT) in a mouse model of asthma, to investigate the effects on airway hyperresponsiveness and IgE, IFN-y levels, Understanding the pathogenesis of asthma more deeper,to provide new ideas for clinical treatment of asthma.Objective:1. By observing the IL-5soluble receptor (sIL-5Ra) combined IL-4mutants in asthmatic mouse model, explore its effects on airway hyperresponsiveness(AHR), understand the asthma pathogenesis more in-depth, provide more effective means for treatment of asthma. 2. By observing the IL-5soluble receptor (sIL-5Ra) combined IL-4mutants in a murine model of asthma, to discuss its effects on IgE, IFN-γ levels in asthma mouse serum and bronchoalveolar lavage fluid (BALF),as to further understand the potential value of multilayer surface intervention targeting the treatment.Methods:1. Divided50female BALB/c mice into five groups randomly, they were the normal control group, asthma group, IL-4MT treatment group, sIL-5Ra treatment group and IL-4MT combined with sIL-5Ra treatment group (combined treatment group). All the mice except for mice in normal control group were sensitized by intraperitoneal injection of ovalbumin (OVA) and aluminium hydroxide suspension, atomizated with ovalbumin, established a murine model of asthma, and normal control group mice with saline instead. Mice in IL-4MT treatment group, sIL-5Ra treatment group and combined treatment group were injected respectively with IL-4mutant (100μg), IL-5soluble receptor (100μg), IL-4mutant (100μg) and IL-5soluble receptor (100μg)30minutes before atomization, mice in normal control group and asthma group with saline instead.2.24hours after the last stimulation, induced the mice with different concentrations of acetylcholine chloride, determined the pulmonary resistance, the changes of IgE and IFN-γ levels in serum and bronchoalveolar lavage fluid (BALF) were observed and compared by ELISA, lung tissue were stained with HE, to observe the pathological changes.Results:1.①Compared with the normal control group, Lung resistance in asthmatic mice increased significantly (P<0.01)[(6.46±0.62) cmH20/(ml·s) vs (4.07±0.53) cmH2O/(ml·s);(12.01±1.79) cmH20/(ml·s) vs (7.36±0.47) cmH20/(ml·s)],when the concentration of acetylcholine chloride were20μg/mL and40μg/mL.②Compared with the asthma group, pulmonary resistance of mice in IL-4MT treatment group at the concentration of acetylcholine chloride was40μg/mL decreased significantly (P<0.05)[(9.04±0.97) cmH20/(ml·s) vs (12.01±1.79) cmH20/(ml·s)], mice pulmonary resistance of sIL-5Ra treatment group had no significant changes (P>0.05), pulmonary resistance of combined treatment group mice were significantly decreased (P<0.05)[(5.40±0.83) cmH20/(ml·s) vs (6.46±0.62) cmH20/(ml·s);(8.58±0.91) cmH20/(ml·s) vs (12.01±1.79) cmH20/(ml-s)] at the concentration of20μg/mL and40μg/mL.③Compared with the IL-4MT treatment group and sIL-5Ra treatment group, pulmonary resistance of combined treatment group mice remarkably decreased (P<0.05).2.①Compared with the normal control group, the content of IgE in serum and BALF in asthma group significantly increased [(411.96±26.56) ng/mL vs (137.29±19.69) ng/mL and (27.65±0.71) ng/mL vs (3.60±0.97) ng/mL], the content of IFN-γ significantly reduced [(336.46±80.81) pg/mL vs (672.94±48.86) pg/mL and (89.31±26.66) pg/mL vs (219.30±50.03) pg/mL],the difference were statistically significant (P<0.01).②Compared with the asthma group,the content of IgE in serum and BALF in IL-4MT treatment group, sIL-5Ra treatment group and combined treatment group mice decreased significantly (P<0.01)[(305.16±10.22) ng/mL、(11.86±0.74) ng/mL and (302.38±14.95)ng/mL、(12.96±0.86) ng/mL and (242.08±42.29) ng/mL、(8.67±1.02) ng/mL], the content of IFN-γ was significantly increased (P<0.05)[(489.77±53.49) g/mL、(137.81±16.75)pg/mL;(490.51±83.54) pg/mL、(123.77±22.67) pg/mL] and (P<0.01)[(588.82±74.29) pg/mL、(181.78±26.46)pg/mL].③Compared with the IL-4MT treatment group and sIL-5Ra treatment group, IgE level in serum and BALF in combined treatment group decreased more obviously, IFN-γ level elevated more greatly.Conclusion:Combined application of IL-4mutant and IL-5soluble receptor in asthmatic mice can significantly reduce AHR, IgE in serum and BALF and increase the content of IFN-γ, thereby reducing asthma inflammatory reaction, provides new possibilities for clinical treatment of asthma.