Investigate The Role Of Atopy In Np From Th17/Treg Imbalance

Background and Objectives Nasal polyposis (NP), commonlyencountered in clinical otorhinolaryngology, is a chronic inflammatorydisease of the nasal cavity and sinus. Nowadays the treatment outcomes ofantibiotics, steroids, and surgery for NP are unsatisfactory, and therecurrence rate remains high. NP has become a more and more importantsocial issue because of its high incidence and considerable economic burden.Over the last2decades, the pathogenesis of NP has been studied widely, butit is not clearly understood yet, and the role of atopy in the etiology andpathogenesis of NP is still a controversial issue. Nowadays NP is consideredto be a multifactorial disease and generally represent a subset of chronicinflammation of the mucous membrane in the paranasal sinus, which isdistinct from chronic rhinosinusitis without NP. A variety of allergic,infectious, inflammatory and anatomical factors are known to be involved inthe origin of NP.Recently, Th17cells and regulatory T (Treg) cells have been describedas two subsets distinct from Th1and Th2cells. Th17cells are characterizedby their preferential production of interleukins (IL)-17A and F and requireretinoid orphan nuclear receptor (RORc) as a key transcription factor for their differentiation in humans; Th17cells play critical roles in thedevelopment of autoimmunity, inflammation and allergic reaction. Treg cellsexpressing the forkhead/winged helix transcription factor (Foxp3) arethought to maintain immunological self-tolerance and have ananti-inflammatory role that functions by contact-dependent suppression orby releasing anti-inflammatory cytokine IL-10and transforming growthfactor (TGF-β). Th17and Treg not only exhibit opposite functions in theimmune response but also share reciprocal development pathways. Theimbalance of Th17/Treg still exists in patients with juvenile arthritis,primary nephritic syndrome and inflammatory bowel disease, suggestingthat the imbalance of Th17/Treg may be a feature of pathologicinflammatory disease and play an important role in the pathogenesis ofchronic inflammatory disease.In this study, we divided NP patients according atopy or non-atopy, andthe TH17/Treg balance was designed as the entry point. We evaluated theimmune characteristics of NP patients with atopy or not, in order todetermine the different features of Th cells dysfunction in NP patients withatopy or not, and discuss the possible correlation between atopy and NP. Thisresearch will open a new avenue, provide new targets for the research of NP,and improve the Th cell imbalance theory in the pathogenesis of NP. Thisresearch can provide a new breakthrough for the establishment of controlstrategies for NP. Part one The difference in some clinical and pathologicalcharacteristics between nasal polyposis patients with and without atopyObject: we aimed to observe the clinical characteristics andhistological features of atopic and non-atopic NP patients, and then analyzethe differences and correlations between two groups, finally investigate therole of atopy in the pathogenesis of nasal polyposis.Method: NP patients in our department from2010.1-2010.10werecollected. The diagnosis of NP was made according to the current EuropeanEAACI Position Paper on Rhinosinusitis and Nasal Polyps and Americanguidelines. NP patients were divided into atopic or non-atopic NP groupbased on skin prick test (SPT). Clinical data and polyp tissue were collected.Symptom scores were assessed according to a visual analog scale (VAS).The preoperative computed tomography (CT) scans were graded accordingto the classification by Lund and Mackay. The preoperative nasal endoscopyscores were graded according to the classification by Lanza and Kennedy.The polyp tissue sections were stained with hematoxylin and eosin (H-E).Maximal basement membrane (BM) thickness and the number ofeosinophils were detected at a magnification of×400.Results: Forty-six patients (24males,22females;26atopic,20non-atopic) between23and70years of age were included. Endoscopy score,and CT score were significantly higher in the atopic group than in the non-atopic group. However, no statistically significant differences werefound between two groups from the standpoint of symptom score, age, sex,duration of disease or recurrence, and asthma was only noted in the atopicgroup. Histologically, the mean number of eosinophils in the atopic groupwas significantly increased compared to that of the nonatopic group. TheBM was statistically thicker in atopic compared to nonatopic patients.Conclusion: In atopic NP patients, there were more severe clinical andhistological features. Atopy may aggravate NP by promoting the infiltrationof EOS in polyp tissue. In the treatment of NP, it is necessary to distinguishthe atopic NP patients from non-atopic ones, and provide them activelyanti-allergy treatment. Atopic constitution can be used as a sub-classificationfor NP to guide clinical treatment.Part two Impaired balance of Th17/Treg in patients with nasalpolyposisObject: To assess whether the balance of Th17/Treg is disrupted inpatients with NP, we evaluated the distribution of Th17and Treg cells amongperipheral blood mononuclear cells (PBMCs) in atopic NP patients,non-atopic NP patients and controls.Method: We evaluated the distribution of Th17and Treg cells amongperipheral blood mononuclear cells (PBMCs) in atopic NP patients,nonatopic NP patients and controls. Then we determined mRNA levels of RORc, Foxp3and protein levels of IL-17, TGF-β and IL-10in polyp tissueamong the three groups. Finally, we investigated the correlation betweenTh17, Treg and Th1, Th2related cytokines (INF-γ, IL-4, IL-5).Results: The results demonstrated that both atopic and non-atopicpatients with NP revealed significantly increased Th17proportion anddecreased Treg proportion in PBMCs, as well as significantly increasedRORc and IL-17levels and decreased Foxp3and TGF-β levels in polyptissue. Furthermore, these differences were significant between atopic andnon-atopic groups. The frequency of Treg in PBMCs was found to benegatively correlated with Th1and Th2cytokines in polyps.Conclusion: These results indicated that an impaired balance ofTh17/Treg existed in patients with NP and was more severe in atopic patients,suggesting that the imbalance of Treg Th17may play an important role inthe development of NP and that atopy may aggravate NP by promoting theimbalance of Th17/Treg. The imbalance of Th1/Th2in NP may be ascribedto decreased regulation of them by Treg.Part three Allergen induced Th17and Treg cells response in theperipheral blood mononuclear cells (PBMCs) of patients with nasalpolyposisObject: This study aimed to investigate the population and function ofperipheral Th17and Treg cells in response to HDM allergen in NP patients, and evaluate the possible correlation between Th17/Treg cells and atopy, toexplore the role of atopy in the pathogenesis of NP.Methods: Peripheral blood mononuclear cells (PBMC) obtained fromatopic NP patients, non-atopic NP patients, and controls were stimulated byphytohemagglutinin (PHA) or house dust mite extracts (HDM) plus PHA.The resulting frequency of Th17and Treg cells was detected by flowcytometry and the expression of RORc and Foxp3was measured byreal-time PCR. Then the supernatants were assayed for IL-17, TGF-β,IL-10,INF-γ, IL-4and IL-5by specific ELISAs.Results: The population and function of Th17cells in allergenstimulated PBMCs were significantly higher in atopic NP patients. Inaddition, in atopic group, HDM+PHA stimulation induced significantincrease of Th17population and IL-17production versus those in PHAstimulated ones. However, the frequency of Th17cells was not correlatedwith Th1, Th2cytokine productions. Both atopic and non-atopic NP patientsrevealed significantly decreased frequency of Treg cells and Foxp3level inallergen stimulated PBMCs, as well as significantly decreased TGF-β levelin culture supernatants. The decrease was even more striking in atopic group.Also, there were significant negative correlations between Treg cells andINF-γ, IL-4, IL-5.Conclusion: Th17and Treg immunity is involved in the systemicimmune responses to allergen in atopic NP and atopy may aggravate NP by stimulating the increase of Th17population and decrease of Treg production.Patients with NP had a defective regulatory T cell response after allergenstimulation which was related to the excessive Th1, Th2responses tospecific allergen.