【作者】 朱俊；

【导师】 沙泉；

【作者基本信息】 安徽医科大学 ， 免疫学， 2007， 硕士

【摘要】 背景：呼吸道感染通常是导致哮喘、慢性鼻窦炎、慢性阻塞性肺病加重的主要原因。在呼吸道中，致密的黏膜上皮细胞被认为具有重要的机械屏障作用；然而越来越多的证据证实呼吸道黏膜上皮细胞在感染和过敏刺激中发挥关键性主动防御作用。但是，上皮细胞在固有免疫或适应性免疫应答中确切机制仍然不太清楚。目的：阐明呼吸道上皮细胞在呼吸道固有免疫应答中所起的作用并初步探讨其分子作用机制；初步探讨IL-10、C3、C4、C1q在鼻息肉中的表达及其意义。方法：常规体外培养A549细胞，细胞传代24h后加入灭活的E.coli，进行不同浓度或时间的诱导；运用半定量RT-PCR法检测其细胞中IL-6、C3和CRP mRNA水平；ELISA法检测其上清液中IL-6、CRP和SAA蛋白水平，免疫比浊法检测其上清液中C3蛋白水平。免疫组化SABC法检测IL-10、C3、C4、C1q在38例鼻息肉和14例正常下鼻甲组织中的表达，对IL-10、C3、C4、C1q阳性细胞的类型、分布进行分析。结果：培养的A549细胞在不同浓度和不同时间的E.coli诱导下，进行IL-6、C3和CRP mRNA以及IL-6、C3、CRP和SAA蛋白水平表达的测定，呈浓度和时间的依赖性；与对照组相比，差异均有显著性(P＜0.05)。IL-10、C3、C4、C1q主要表达于鼻息肉的上皮细胞及炎性细胞中，较正常下鼻甲组织明显增强，差异有显著性(P＜0.01)。结论：呼吸道上皮细胞在病原微生物刺激下，表达许多非特异性免疫效应分子，这些分子积极清除外来致病物，发挥重要的固有免疫防御作用；上皮细胞还可能在固有免疫和适应性免疫之间架起一座桥梁。免疫组化法证实IL-10、C3、C4、C1q在鼻息肉组织内的上皮细胞和多种炎性细胞中明显表达，能客观反应免疫或炎症反应的程度，提示IL-10、C3、C4、C1q在局部的抗感染和炎症中可能起着重要作用。更多还原

【Abstract】 Background: Respiratory infections are thought to be a leading cause of exacerbationof several airway diseases including asthma, chronic rhinosinusitis and chronicobstructive pulmonary disease. The epithelium is thought to serve an important barrierfunction in the airways. However, growing evidence supports the notion that therespiratory epithelium plays a key role in host responses to infectious and allergenicstimuli. The clear mechanism(s) by which it plays in both the innate and adaptiveimmune response of the airways are not well understood.Objective: To investigate important roles of the respiratory epithelium and theunderlying mechanisms in the innate immune response of the airways. To evaluate theexpression and significance of IL-10、C3、C4、C1q in the pathophysiology of nasalpolyps.Methods: Human pulmonary epithelial-derived cell line A549 was cultured. Heat-inactivated E.coli in different concentration was added 24h after the cells were seeded.The cells were harvested and supernatant were collected at different time points. Theexpression of IL-6, C3 and CRP at the mRNA levels from cells were measured bysemi-quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis.The expression of IL-6, CRP, SAA and C3 at the protein level in the supematant wasmeasured by enzyme-linked immunosorbent assay and immunonephelometry. Theexpression of IL-10、C3、C4、C1q were determinated in 38 tissue samples of nasal polyps and 14 controls from normal inferior turbinates by immunohistochemicalmethod, respectively. The cell types and distributed were analysed in positiveexpression of IL-10、C3、C4、C1q.Results: Heat-inactivated E.coli at different concentrations and for different timeinduced the expression of IL-6, C3 and CRP mRNA and the secretion of IL-6, C3,CRP and SAA in A549 cells with a concentration- and time-dependent manner. Thedifference between each experimental groups and control groups was significant(P＜0.05). There was a significant over-expression of IL-10、C3、C4、C1q in nasalpolyps compared to normal inferior turbinates. The difference between these two groupswas significant (P＜0.01). IL-10、C3、C4、C1q-positive cells were localized inepithelium and inflammatory cells in nasal polyps.Conclusions: The respiratory epithelium produces a lot of nonspecific immunologicalmolecules in host responses to infectious stimuli. These molecules eliminatemicroorganisms positively and play important roles in host responses to infectious. Theepithelium may act as a bridge between innate and adaptive immunity at the mucosalsurface of the airways. IL-10、C3、C4、C1q may play some important roles with localanti-bacterial properties and anti-inflammatory effects in nasal polyps.更多还原