OVA致敏小鼠中枢性免疫器官—胸腺TSLP、Foxp3的表达及调节

发布时间：2018-07-03 12:44

本文选题：胸腺基质淋巴生成素 + 胸腺肽　；参考：《复旦大学》2008年硕士论文

【摘要】： 目的近20年来,包括哮喘、过敏性鼻炎、特应性皮炎和食物过敏在内的过敏性疾病在经济发达国家的发病率逐年升高。在一些西方发达国家,哮喘的发病率高达29%。哮喘是儿童时期最常见的慢性疾病之一,自1980年以来,我国儿童哮喘的发病率增加了近1倍。研究证实从特应性皮炎、食物过敏、过敏性鼻炎至哮喘的“过敏历程(Allergy marches)”,提示可能存在共同的始动因素。目前,过敏性疾病的发病机制仍不明确,治疗方法也没有新的突破。普遍认为过敏性炎症反应是一系列复杂的免疫级联反应,表现为Th1/Th2平衡破坏向Th2倾斜,分泌Th2型细胞因子(如:IL-4、5、13),这些细胞因子又进一步触发IgE合成、嗜酸性粒细胞增多及粘液分泌。多数研究集中在外周免疫器官和免疫细胞上,对中枢性免疫器官——胸腺,在过敏性疾病发病机制中的作用知之甚少。最新的研究发现,胸腺基质淋巴生成素(Thymic stromal lymphopoietin,TSLP)在外周能激活DC产生Th2应答优势的炎症反应,在胸腺能诱导自身反应性T细胞成为调节性T细胞,从而发挥控制炎症反应的作用,提示TSLP可能是过敏性炎症反应的一个重要促发因素,胸腺可能在过敏性疾病的发病机制中起重要作用。胸腺肽作为一种免疫调节剂,在临床运用多年,对常规治疗难以控制的哮喘和特应性皮炎有一定的治疗效果。胸腺肽是一种胸腺组织上皮细胞分泌的多肽激素,推测其可能通过调节胸腺功能间接影响过敏性疾病的发展。因此,本研究通过OVA致敏建立小鼠哮喘模型,探讨TSLP、胸腺在过敏性疾病发病机制中的作用,同时用胸腺肽进行干预,研究胸腺肽干预致敏的作用和可能机制。方法 1、采用OVA腹腔注射和超声雾化吸入建立BALB/c小鼠哮喘模型; 2、通过血清总IgE水平和肺组织病理切片来评价模型; 3、用Real-time PCR检测OVA致敏和胸腺肽干预的不同情况下,小鼠胸腺、肺组织TSLP、Foxp3表达的变化以及肺组织IFN-γ、IL-4表达的变化,IFN-γ/IL-4比值的变化;并通过血清总IgE水平和肺组织病理切片来评价胸腺肽干预下致敏小鼠的过敏状态。结果 1、血清总IgE浓度比较:致敏组与对照组相比,血清总IgE浓度增加,差异有显著统计学意义(P＜0.05);OVA+胸腺肽组与致敏组相比,差异无统计学意义(P＞0.05);单独胸腺肽干预组与对照组相比,差异无统计学意义(P＞0.05)。 2、肺组织病理切片比较(HE染色):致敏组肺组织病理切片示气道壁明显增厚,黏膜下及管壁周围有较多炎性细胞浸润。对照组气道炎症反应轻,上皮增厚不明显,气道周围炎性细胞浸润少,肺泡壁结构相对完整。OVA+胸腺肽组与致敏组相比气道炎症反应较轻,管壁旁少量炎性细胞浸润,管壁无明显增厚。 3、致敏对小鼠胸腺、肺组织TSLP和Foxp3 mRNA表达的影响:致敏组小鼠胸腺TSLP mRNA表达高于对照组,差异具有非常显著的统计学意义(P＜0.01);胸腺Foxp3 mRNA表达低于对照组,差异具有显著统计学意义(P＜0.05)。致敏组肺组织TSLP mRNA表达同样高于对照组,差异具有显著统计学意义(P＜0.05);肺组织Foxp3的表达与对照组相比,差异无统计学意义(P＞0.05)。 4、胸腺肽干预对致敏小鼠胸腺、肺组织TSLP和Foxp3 mRNA表达的影响:与致敏组相比,OVA+胸腺肽干预组胸腺TSLP mRNA的表达明显减少,差异具有非常显著的统计学意义(P＜0.01);胸腺Foxp3 mRNA的表达与致敏组比较差异无统计学意义(P＞0.05)。OVA+胸腺肽干预组小鼠肺组织TSLP、Foxp3mRNA的表达与致敏组比较,差异均无统计学意义(P＞0.05)。 5、单独胸腺肽干预对小鼠胸腺、肺组织TSLP和Foxp3 mRNA表达的影响:单独胸腺肽干预组胸腺、肺组织TSLP的表达与对照组相比,差异无统计学意义(P＞0.05)。单独胸腺肽干预组胸腺Foxp3 mRNA表达低于对照组,差异具有非常显著的统计学意义(P＜0.01);而肺组织Foxp3的表达高于对照组,差异具有显著的统计学意义(P＜0.05)。 6、OVA致敏和胸腺肽干预的不同情况下,小鼠肺组织IL-4、IFN-γmRNA表达的变化:致敏组肺组织IL-4 mRNA的表达与对照组相比,差异无统计学意义(P＞0.05);IFN-γmRNA的表达低于对照组,差异具有非常显著的统计学意义(P＜0.01);两组IFN-γ/IL-4比值比较,差异无统计学意义(P＞0.05)。OVA+胸腺肽干预组肺组织IL-4、IFN-γmRNA表达与致敏组相比,差异均无统计学意义(P＞0.05),两组IFN-γ/IL-4比值比较,差异无统计学意义(P＞0.05)。单独胸腺肽干预组肺组织IL-4、IFN-γmRNA表达与对照组相比,差异均无统计学意义(P＞0.05),两组IFN-γ/IL-4比值比较,差异无统计学意义(P＞0.05)。结论 1、OVA致敏能同时上调胸腺和肺TSLP的水平,提示致敏本身能影响到中枢性免疫器官——胸腺。 2、OVA致敏能使胸腺内TSLP诱导的Tr分化下调,提示胸腺功能的改变可能与过敏性疾病的发生有关。 3、胸腺肽干预致敏可下调胸腺TSLP表达,提示胸腺肽治疗过敏的机制至少部分是通过胸腺发挥作用。
[Abstract]:In recent 20 years , the incidence of allergic diseases , including asthma , allergic rhinitis , atopic dermatitis and food allergy , has increased year by year . In some western developed countries , the incidence of asthma is 29 % .

method

1 . BALB / c mice model was established by intraperitoneal injection of OVA and ultrasonic atomization inhalation .

2 . The model was evaluated by serum total IgE level and pathological section of lung tissue ;

3 . The changes of the expression of IFN - 纬 , IL - 4 and IFN - 纬 / IL - 4 in the thymus , lung tissues , TSLP , Foxp3 and IFN - 纬 / IL - 4 were detected by Real - time PCR .

Results

1 . Compared with the control group , the serum total IgE concentration in the sensitized group was significantly higher than that in the control group ( P < 0.05 ) , and the difference was not statistically significant ( P > 0.05 ) .

2 . Comparison of pathological sections of lung tissues ( HE staining ) : The pathological sections of lung tissues in the sensitized group showed obvious thickening of the airway wall , and there were more inflammatory cell infiltration around the mucous membrane and around the wall .

3 . The effect of sensitization on the expression of TSLP and Foxp3 mRNA in the thymus and lung tissues of mice was significantly higher than that in the control group ( P < 0 . 05 ) . The expression of TSLP mRNA in the lung tissues of the sensitized group was significantly higher than that of the control group ( P < 0 . 05 ) .

4 . The effects of thymosin on the expression of TSLP and Foxp3 mRNA in thymus and lung tissues of sensitized mice showed that the expression of TSLP mRNA in the thymus of OVA + thymosin group was significantly decreased compared with that in the sensitized group ( P & lt ; 0.01 ) . The expression of Foxp3 mRNA was not statistically significant ( P > 0.05 ) . The expression of Foxp3 mRNA was not statistically significant ( P > 0.05 ) .

5 . The effect of single thymosin intervention on the expression of TSLP and Foxp3 mRNA in thymus and lung tissues of mice was significantly higher than that in the control group ( P > 0.05 ) .

Compared with the control group , the expression of IL - 4 and IFN - 纬 mRNA in the lung of the sensitized group was significantly higher than that in the control group ( P > 0.05 ) .

Conclusion

1 . OVA sensitization can increase the level of thymus and lung TSLP at the same time , suggesting that sensitization can affect the central immune organs _ thymus .

2 . OVA sensitization can downregulate Tr differentiation induced by TSLP in thymus , suggesting that changes in thymus function may be related to the occurrence of allergic diseases .

3 . The effect of thymosin on the expression of TSLP in thymus can be downregulated . It is suggested that the mechanism of thymosin treatment is at least partly mediated by thymus .
【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R725.6;R392

【参考文献】