Differential Expression And Significance Of IL-35 In Asthmatic Subtypes

Background:Asthma is a heterogeneous chronic inflammatory Airway disease characterized by airway hyperreactivity(AHR)and reversible airway obstruction.AHR involved in the increase in bronchoconstriction caused by the infiltration of inflammatory cells and release of inflammatory cytokines.Asthma is characterised by chronic airway inflammation caused by an abnormal T cell response.The exudation of CD4+T lymphocytes(LY)(including Thl,Th2 and Th17 cells)is associated with the development of airway inflammation.While in the process of asthma research,allergen induced the Th2 lymphocytes and Interleukin 5(IL-5)mediated eosinophils(EOS)response in has been fully proved,but recent research suggests that as much as 50%of asthma patients without evidence of Eosinophil inflammation,and this type of asthma is called Non-eosinophils asthma(NEA).This fully demonstrates that asthma is a heterogeneous disease.At present,a large number of basic and clinical experimental results reveal the "asthma subtype" classified by the percentage of induced phlegm inflammatory cells,which can reflect different pathogenesis and different clinical treatment characteristics.The specific classification methods are as follows:Neutrophilic asthma(NA)(EOS<3%,Neutrophil(NEU)>61%),Mixed granulocytic asthma(MA)(EOS>3%,NEU>61%),Both Paucigranulocytic asthma(PA)(EOS<3%and NEU<61%)and Eosinophilic asthma(EA)(EOS>3%and NEU<61%).Because each subtype has obviously altered immunological mechanisms,each subtype also has different responses to treatment,which provides a new basis for the "individualized treatment" of asthma.EA responds well to corticosteroids,which are used as first-line therapies.NA,on the other hand,is driven by innate immune system activation caused by infection and environmental pollutants and is less responsive to inhaled corticosteroids,but recent research suggests that actinomycin may be responsible for this type of asthma attack.In recent years,many studies have shown that each subtype has unique mechanisms and different responses to treatment.The newly discovered Interleukin-35(IL-35)has significant anti-inflammatory activity and plays an important part in regulating allergic airway inflammation.Research has shown to give the airway exogenous IL-35.Inhibits Th2 cells function in mice,inhibit allergic airway inflammation,and can inhibit the allergy source specific Immunoglobulin E(IgE)reaction.Further studies showed that IL-35+T cells could inhibit the allergic airway hyperresponsiveness mediated by Th17 cells.Clinical studies have shown that the level of IL-35 in the serum of asthma patients is reduced and negatively correlated with clinical symptoms and lung function,while the level of serum IL-35 and the expression of IL-35 mRNA in peripheral blood cells are significantly negatively correlated with the number of IL-4+Tc2 and IL-17a+Tc17 cells.On the contrary,another study reported that the serum IL-35 expression of asthma patients was significantly higher than that of normal people.The inconsistency of these findings illustrates the heterogeneity of asthma pathogenesis.Currently,there is not any relevant report on the difference in the expression of IL-35 in the inflammatory subtype of asthma.Objectives:In this study,the expression of IL-35 in induced sputum supernatant was detected to investigate the differential expression of IL-35 in inflammatory subtypes of asthma and the pathophysiological mechanism of IL-35 in different subtypes.Methods:1.Asthma patients and healthy volunteers were randomly selected to the outpatient department of the second hospital of Jilin university for reexamination according to the induced sputum revision program.All participants were examined(lung function examination,FeNO,blood test)and basic infornation of the patients was collected.In this study,asthma subtypes were identified according to the classification criteria of induced phlegmy inflammatory cells proposed by Gibson PG.2.The expression levels of IL-35,Interleukin-9(IL-9)and Interleukin-37(IL-37)inflammatory cytokines in asthma patients and healthy volunteers were detected by ELISA,and flow cytometry was used to detect other related factors in induced sputum supernatant of multi-factor detection.It mainly includes Interleukin 1?(IL-1?),Interleukin 6(IL-6),Interleukin 8(IL-8),Interleukin 10(IL-10),Interleukin 12p70(IL-12p70),and Interleukin 17A(IL-17A),Interleukin 18(IL-18),Interleukin 23(IL-23),Interleukin 33(IL-33),Interferon-y(INF-?),Tumor necrosis factor-?(TNF-?)and Monocyte chemoattractant protein-1(MCP-1)were used to compare the differences in the expression levels of inflammatory factors,such as lung function,FeNO and blood test,between the asthma group and the healthy group.Results:1.Clinical characteristics of the subjects and the expression of IL-35 in different subjects:(1)The subjects were 114 asthma patients and 20 healthy volunteers,among which 90 patients and 19 healthy volunteers were eligible for sputum smear induction.(2)General conditions of subjects in the two groups were not statistically significant;(3)Opposed to the healthy group,asthma group had significantly higher FeNO(P<0.05)and significantly lower lung function indicators(FEV1,FVC,FEV1/FVC,FEV1%predicted value)(P<0.05).(4)The total number and percentage of eosinophils in the induced sputum smear of the asthma group was significantly higher than that of the healthy group(P<0.05),and macrophages were significantly lower than that of the healthy group(P<0.05).(5)The IL-35 level of sputum supernatant in the asthma group[4.89(2.99,22.54)ng/ml]showed no significant difference compared with the healthy control group[6.01(4.15,2.79)].2.Phenotypic characteristics of inflammatory cells in asthma and the difference in the expression level of IL-35 in the classification of asthma:There were 39 cases of PA(43.33%).MA in 9 cases(10%);NA in 4 cases(4.44%).The NA level of IL-35 was the highest[40.59(21.63,62.52)],followed by PA[6.25(3.19,23.44)]and MA[22.54(2.59,45.69)],while the EA level was the lowest[3.96(2.84.10.92)1.The difference was statistically significant(P<0.05).3.The relationship between IL-35 and other inflammatory factors,FeNO and FEV1/FVC and so on:IL-35 is negatively correlated with FeNO and FEV1/FVC,negatively correlated with the total number of eosinophils in the sputum superstratum,and positively correlated with the total number of neutrophils in the sputum superstratum.IL-35 was significantly corelated with IL-1?,IL-6,IL-8,1L-10,IL-12p70,1L-17A,IL-23,IL-33,IFN-?,TNF-?,and MCP-1.Conclusions:1.Different asthma phenotypes have different clinical characteristics:EA is younger.MA has the worst lung function,and PA has the best lung function.2.IL-35 in induced sputum supernatant is closely linked to the phenotype of asthma,with the lowest expression in eosinophilic asthma and the highest expression in neutrophil asthma.At the same time,the expression of eosinophilic asthma was much lower than that of non-eosinophilic asthma.3.IL-35 in induced sputum supernatant can predict the severity and subtype of airway inflammation in patients.4.Combined with the analysis of the correlation between other inflammatory factors and IL-35,it can be inferred that IL-35 promotes neutrophil asthma inflammatory response and inhibiting eosinophilic asthma inflammatory response,which is expected to provide a new research direction for the classification,diagnosis and treatment of asthma in the future.