Molecular analysis of relationship between airway hyperreactivity and inflammation

基因芯片分析显示，过敏原吸入后6h，CCL21(原次级淋巴组织趋化因子，SLC)和CCL19显著升高。CCL21是初始T细胞和抗原刺激的DC进入次级淋巴器官T细胞区的关键趋化因子，是抗原特异性T细胞活化的关键过程。在这项研究中，我们利用同时存在CCL21和CCL19基因表达缺陷的BALB/c-PLT/PLT小鼠(PLT小鼠)，研究了CCL21在哮喘气道炎症中的作用。用卵白蛋白(OVA)和明胶免疫BALB/c小鼠4次，然后进行为期2周的OVA吸入治疗。虽然与BALB/c小鼠相比，气道炎症和对乙酰胆碱的反应显著减少，但PLT小鼠也观察到明显的嗜酸性炎症和高反应。停止吸入4周后，呼吸道炎症和高反应性…PLT小鼠的吞噬能力强于BALB/c小鼠。为了阐明呼吸道炎症延迟消退的机制，我们用流式细胞术分析了T细胞上CCR7、CCL19和CCL21的受体，因为有报道说CCR7的表达是T细胞从外周组织中退出的关键。PLT小鼠呼吸道内可见CD4+CCR7+细胞，但以CD4+CCR7-细胞为主。停止吸入OVA 7天后，PLT小鼠BALF中CD25阳性的CD4细胞数量和IL-10的产生明显少于BALB/c小鼠。综上所述，CCL21和CCL19不仅在诱导和缓解气道炎症中起关键作用。为了阐明T细胞在气道高反应性中的作用，我们重点研究了GATA-3，它是Th2细胞产生Th2细胞因子的必要条件，旨在阐明GATA-3高表达的T细胞在体内哮喘的病理生理学中的作用。使用携带GATA-3基因和卵清蛋白(OVA)特异性T细胞受体基因(GATA-3-TG(+))的双转基因小鼠。结果显示，GATA-3-TG(+)小鼠的呼吸道IL-13和IL-4蛋白水平显著升高。尽管GATA-3-Tg(+)组和GATA-3-Tg(-)组小鼠鼻腔注射OVA第7天时，GATA-3-Tg(+)组和GATA-3-Tg(-)组小鼠鼻腔注射乙酰胆碱后的反应性明显高于GATA-3-Tg(-)组，且GATA-3-Tg(-)组和GATA-3-Tg(-)组小鼠的免疫球蛋白E水平均未见明显升高。这种高反应性可被5-脂氧合酶抑制剂抑制。综上所述，哮喘的特征之一--呼吸道高反应性是通过在体内转录水平上控制淋巴细胞来诱导的。较少

Analysis using cDNA array revealed that CCL21 (formerly secondary lymphoid tissue chemokine, SLC) and CCL19 were significantly increased at 6 hours after allergen inhalation. CCL21 is a key chemokine in the entry of naive T cells and antigen-stimulated DCs into the T cell zones of secondary lymphoid organs, which is a critical process in antigen-specific T-cell activation. In the study, we investigated the role of CCL21 in airway inflammation in asthma using BALB/c-plt/plt mice (plt mice), which possess genetic defects in expression of both CCL21 and CCL19. Plt and control BALB/c mice were immunized with ovalbumin (OVA) and alum four times and thereafter were subjected to a two-week regimen of OVA inhalation. Although airway inflammation and response to acetylcholine were significantly reduced compared to BALB/c mice, significant eosinophilic inflammation and hyperresponsivenss were also observed in plt mice. Four weeks after cessation of inhalation, airway inflammation and hyperrespon … More siveness in plt mice were greater than in BALB/c mice. To clarify the mechanisms of delay in resolution of airway inflammation, we performed flow cytometric analysis to assess CCR7, receptor for CCL19 and CCL21 on T cell, because it has been reported that CCR7 expression is critical for T cell exit from peripheral tissues. There were CD4+CCR7+ cells but majority was CD4+CCR7- cells in the airway of plt mice. Seven days after cessation of OVA inhalation, number of CD25 positive CD4 cells and IL-10 production were significantly lesser in plt mice compared to BALB/c mice in the BALF. In conclusion, CCL21 and CCL19 were critical for not only induction but also resolution of airway inflammation.In order to clarify the role of T cell for airway hyperreactivity, we focused on GATA-3, which is essential for Th2 cells to produce Th2 cytokines and aimed to clarify the role of GATA-3 hyperexpressive T cells in the pathophysiology of bronchial asthma in vivo. Double transgenic mice carrying the GATA-3 gene and the ovalbumin (OVA)-specific T cell receptor gene (GATA-3-Tg (+)) were used. As a results, GATA-3-Tg (+) mice exhibited significantly higher IL-13 and IL-4 protein at the airway. Although there was no difference in infiltrated cells between GATA-3-Tg(+) and GATA-3-Tg(-) and no significant increase in IgE level in either group compared to non-treated mice, the response after acetylcholine inhalation was significantly elevated in GATA-3-Tg(+) than in GATA-3-Tg(-) on the seventh day of intranasal treatment with OVA. This hyperresponsiveness was inhibited by 5-lipoxygenase inhibitor. In conclusion, airway hyperresponsiveness, a characteristic of bronchial asthma, was induced by controlling lymphocytes at the transcriptional level in vivo. Less