The Expression Of B7-H1/PD-1 Pathway In Nasal Polyposis

PARTⅠInvestigation of B7-H1/PD-1 costimulatory molecules in nasal polyposisBackground Bilateral nasal polyposis(NP)is a form of chronic sinusitis(CRS) characterized by chronic inflammatory disease of the mucosa of nasal cavity and paranasal sinuses.The overall prevalence rate of NP in the general population ranges from 1%to 4%.The quality of life for NP patients is worse than for patients suffering from hypertension,migraine,angina pectoris,and head and neck cancer.Although some hypotheses exist for how NP develops,the etiopathologenetic mechanisms of the disease are still controversial.The pathogenesis of CRSwNP is though to involve persistent inflammation of the nasal mucosa due to infiltration by eosinophil and other cell types(lymphocytes,mast cells,basophils,and neutrophils).NP is histologically characterized by respiratory epithelium covering edematous stroma and infiltrated inflammatory cells.Recent findings show that eosinophils and lymphocytes are the most common inflammatory cells in NP.However,T lymphocytes are central to the development of sinonasal inflammation.The initiation and regulation of nasal inflammatory responses are absolutely dependent on T-lymphocyte recruitment,activation,and cytokine secretion, which may contribute to eosinophil recruitment and activation.The factors that regulate these aspects of T-cell function are incompletely understood,but may include engagement of T-cell-specific accessory molecules.For efficient T cell activation,T cells require both a TCR-mediated Ag-specific signal and costimulatory signals provided by antigen--presenting cells(APCs). Several different types of leukocytes can act as APCs including dendritic cells, macrophages,and B cells.The B7 family of molecules provides signals that are critical for both stimulating and inhibiting T cell activation.The interaction between B7 and CD28 may determine whether a T-cell response develops.T-cell activation is the result of a balance between positive and negative signals.CD28 and ICOS are positive costimulatory receptors which interact with the ligands of the B7 family present on professional APCs and are essential for activation and proliferation of antigen specific T cells.In contrast,negative signals through cell surface molecules such as CTLA-4 and PD-1 inhibit T-cell activation or induce apoptosis.Recently,several new members of the B7 family have been identified.B7-H1 binds to the Programmed Death-1(PD-1)receptor and their interaction downregulates T cell activation.PD-1 is a type I transmembrane receptor expressed on activated T and B cells.Like CTLA-4,PD-1 contains an ITIM in its cytoplasmic region and acts as a negative regulator of lymphocyte function.Several studies support the concept that the B7-H1/PD-1 pathway plays an important immunoregulatory role in the chronicity of inflammatory disorders.Most theories consider CRSwNP to be the ultimate manifestation of chronic inflammation;therefore, the B7-H1/PD-1 pathway may contribute to CRSwNP.Very few studies have examined the role of the B7--H1/PD--1 pathway in NP.Thus,the effects of B7--H1/PD--1 pathway on inflammation mechanisms of NP are still unknown.The aim of the present study was to determine if the B7--H1/PD--1 pathway contribute to the development of NP.Methods 17 cases of CRSwNP and 11 cases of CRSsNP were involved in this study.We use the real-time PCR to analyse the differential mRNA level in CRSsNP and CRSwNP patients compared with the normal middle turbinate mucosa.Western Blotting was used to validation the difference in protein level.Immunofuoresscent staining was used to localize B7-H1/PD-1 proteins in the sinus mucosa.Results The sinus mucocal of CRSwNP and CRSsNP expressed higher level of B7-H1/PD-1 mRNA than the normal middle turbinate mucosa(P＜0.01,or P＜0.05). The CRSwNP and CRSsNP have no significant difference in B7-H1/PD-1 expression(P＞0.05).The protein level of B7-H1/PD-1 showed the uniformity to mRNA level.Conclusions This study showed that B7-H1/PD-1 gene were up-regulated in the sinus mucocal of CRSwNP and CRSsNP,and costimulatory molecules B7-H1/PD-1 may play a key role in the pathogenesis of nasal polyps. PARTⅡAnalysis of lymphocytes immunophentypes in nasal polyps with flow cytometryObjective The present study evaluated the lymphocyte subpopulations and their expressions of B7-H1/PD-1 using flow cytometry Assay.This information may allow us to determined whether the source of these lymphocyte is from peripheral blood, the common mucosal immune system,or both.Methods Nasal polyps and the corresponding peripheral blood were obtained from 17 CRSwNP patients,the samples and the corresponding peripheral blood were obtained from 11 CRSsNP patients,the normal peripheral blood was obtained as comparison.Flow cytometry was used to detect CD4,CD8,CD3,CD19,CD16 CD56, B7-H1and PD-1 on lymphocytes in nasal polyps and the corresponding peripheral blood.Results Compared with the corresponding peripheral blood lymphocytes,the nasal polyp lymphocytes had significantly fewer CD4 and significantly more CD8 T cells(P＜0.01).There were no significant differences when the peripheral blood CD4 and CD8 T cells were compared with normal controls(P＞0.05).B7-H1 on CD19 B cells in nasal polyps was up-regulated in contrast to that on the corresponding peripheral blood lymphocytes and normal controls(all P＜0.01),and its receptor PD-1 on CD3 T cells was also elevated(all P＜0.01).The CRSsNP patients showed the uniformity to CRSwNP patients.There were no significant differences in CD3T cells and NK cells in the three groups.Conclusions Data support the concept that the nasal polyp lymphocytes subpopulations may be derived from both the local mucosal immune system as well as from migration of peripheral blood lymphocytes. PARTⅢThe expression of IFN-γand IL-10 on T lymphocytes that infiltrate in nasal polypsObjective To investigate the expression of cytokine IFN-γand cytokine IL-10 on T lymphocytes that infiltrate in nasal polyps for searching the pathogenesis of nasal polyps.Methods Nasal polyps tissue samples and the corresponding peripheral blood were obtained fiom 17 patients.Flow cytometry was used to detect the expression of IFN-γand IL-10 of T lymphocytes.Results The expression of IL-10 and IFN-γincreased on CD4~+T cells in nasal polyps(4.75%±0.75%,34.64%±2.94%,respectively)compared with the corresponding peripheral blood(1.55%±0.25%,11.98%±1.36%,respectively)(P＜0.05).The expression of IL-10 and IFN-γincreased on CD8~+T cells in nasal polyps (6.70%±0.66%,55.14%±4.04%,respectively)compared with the corresponding peripheral blood(2.75%±0.40%,24.17%±2.88%,respectively)(P＜0.05).Conclusion The expression of IL-10 and IFN-γon T-lymphocytes in nasal polyps was up-regulated in contrast to that on the corresponding peripheral blood lymphocytes.