低气道超敏反应中鼻源性葡萄球菌肠毒素B对Th2细胞的影响

目的探讨由葡萄球菌肠毒素B（SEB）在慢性鼻炎鼻窦炎（CRS）和哮喘之间联系的作用，并确定来源于CRS的SEB在哮喘发病机制中的作用。方法38例同时患CRS和哮喘病的病人，行鼻内镜手术外科治疗，手术后分别对血清中特异性IgE和细胞因子进行检测，并对CRS和哮喘病的临床症状进行评估，分离培养外周血单核细胞（PBMCs），存在或不存在特异性抗原和SEB的情况下，于培养的PBMCs中观察Th2反应。对照组包括：25例仅患CRS的病人，23例仅患哮喘的病人，20例健康对照。结果鼻窦手术后，同时患CRS和哮喘的病人的临床症状和肺功能有所改善，对照组为单独患CRS病人的临床症状改善。术后细胞因子、IL-4、IL-5较术前明显降低，对照组术前、术后没有明显变化。受特异性抗原刺激，培养的PBMCs产生Th2反应，而SEB在维持Th2反应所必需。对照组没有产生Th2反应。结论与鼻窦炎有关的低气道超敏反应中，细菌超抗原SEB在维持Th2反应过程中起了关键作用。

Staphylococcal enterotoxin B plays a role in sustaining Th2 cell polarization in the low airway hypersensitiveity

Objective To explore the role of SEB in relations between chronic rhinosinusitis(CRS)and asthma,and to determine the contribution of the CRS-derived SEB to the pathogenesis of asthma.Methods A total of 38 patients with both CRS and asthma underwent functional endoscopic sinus surgical treatment.Serum specific IgE and cytokines,clinical symptoms of CRS and asthma were detected after the operation.The peripheral blood mononuclear cells(PBMCs)were separated and cultured.The Th2 response in the cultured PBMCs in the presence or absence of specific antigen and SEB was observed.Twenty-five patients with CRS alone,23 patients with asthma alone and 20 healthy controls without history of asthma or CRS were chosen as the control groups.Results The patients with both CRS and asthma obtained satisfactory results in the improvement of clinical symptoms and lung function tests after sinus surgery.Clinical symptom of the patients with CRS alone were improved after sinus surgery.Compared with the preoperative data,Th2 cytokines,IL-4 and IL-5 decreased significantly after operation.The indexes had no significant changes before and after operation in the control groups.The Th2 response was generated in the cultured PBMCs stimulated by specific antigen,but not in the control groups.Conclusion The results indicate that bacterial superantigen SEB plays a crucial role in sustaining the Th2 response of the low airway hypersensitivity related to sinusitis.