A Mechanism Study About DMBT1 To Protect Allergic Rhinitis In A Murine Model

ObjectiveAllergic rhinitis(AR)is a common otorhinolaryngology disease.Its allergic reaction is condemned to be caused primarily by Th2 immunity.Its high morbidity and worldwide prevalence is on the rise.But there is no effective treatment for AR at present.DMBT1 is a secreted glycoprotein that mainly secreted from epithelial cells,and is expressed in the whole immune system.It is reported that abnormal expression of DMBT1 is associated with inflammation and tumor.Our preliminary studies have shown that expression of DMBT1 in patients with allergic rhinitis were significantly different from control group,both in gene level and protein level,which speculated that the protein is related with allergic rhinitis disease.It is therefore necessary to conduct an in-depth basic research on those correlative mechanism.MethodsWe first detected the concentration of DMBT1 protein in nasal lavage fluid by ELISA,and detected the expression of DMBT1 protein in nasal turbinate mucosa by immunohistochemical,in both allergic rhinitis patients and normal persons.Next,BALB/c mice were sensitized and challenged with OVA(ovalbumin)to induce AR model.The nasal mucosa of them were then be collected and detected by Western blot,immunohistochemistry and immunofluorescence,to ensure the expression of DMBT1 in control mice and OVA group.In addition,we established various groups by instilled intranasally different concentrations of recombinant DMBT1 protein in AR mice,observed the symptoms score of mice,detected Th2 cytokines concentration in bronchoalveolar lavage fluid(BALF)by ELISA,and counted eosinophils(EOS)infiltration by HE(Hematein Eosin,HE)staining in nasal mucosa.Results1.The concentration of DMBT1 protein in nasal lavage fluid of patients with allergic rhinitis was up-regulated by ELISA.The expression of DMBT1 protein in inferior turbinate mucosa was significantly up-regulated by immunohistochemistry in patients with allergic rhinitis.2.BALB / c mice were treated with OVA + aluminum adjuvant and the changes of allergic rhinitis were all in accordance with behavioral,histological and immunological functions(peripheral blood OVAsIgE assay),which show that AR model in mice were being established with success.The results of Western blot,immunohistochemistry and immunofluorescence showed that the expression of DMBT1 protein in nasal mucosa was significantly higher than that in saline control group(n=5,P <0.05).3.After we intranasally instilled the recombinant human DMBT1 protein,mice with AR has significantly desrease in indeses,including behavioral score(nose rubbing and sneezing times in 10 min),concentration of Th2 cytokines in the BALF,and infiltration of eosinophil in nasal mucosa.(The differences between groups were statistically significant,n=5,P <0.05)Conclusion1.It was the first time that we found DMBT1 can be secreted to the nasal cavity.It was the first time that DMBT1 expression was elevated in the nasal mucosa of patients with AR.2.The model of AR mouse can be successfully established by the intervention of OVA + aluminum adjuvant in BALB/c mice;and the expression of DMBT1 protein in nasal mucosa of AR group is significantly increased,suggesting that the model of AR provide suitable animal experimental objects to study the effect of DMBT1 on AR.3.For the first time we found that DMBT1 has an inhibitory effect on Th2 cells.