IL-10及Breg调节1-3-β-葡聚糖所致肺部炎症Th应答启动、类型及其调控的机制研究

With the rapid development of the modern industry and agriculture, the occupational environment was polluted by complicated organic dust. Occupational allergic alveolitis, mainly induced by the high-dose fugues contamination, draw more and more wide attention. The infiltration of inflammatory cells and the formation of granuloma were the fundamental pathological characters. however, the mechanism of the immunological modulation during the pathology process is not still clearly demonstrated. Regulatory T cell (Treg) immune took part in regulating the development in allergic alveolitis by affecting its Th immune response according to our previous finding. Recent studies suggested that the regulatory B cell (Breg) took part in kinds of inflammatory diseases. And Breg might also play a crucial role in controlling the Th immune response and its regulation by secreting the repressive cytokine (IL-10) or influencing the activation of macrophage and Treg. Whereas, the detailed mechanism of Breg in regulating the development of allergic alveolitis is unclear. By observations and studies on 1-3-β-glucan, the major constructive composition of fugues, induced lung inflammation in mice, our project was aimed at illustrating the regulatory mechanism of IL-10 and Breg on the activation and regulation of Th immune response at both cellular and molecular level. It is believed that if we demonstrated the mechanism of of IL-10 and Breg on the activation and regulation of Th immune response successfully, the powerful experimental and theoretical foundation will be provided to help delaying and inhibiting the development of occupational allergic alveolitis.

现代工农业生产的快速发展使作业环境中几乎无例外的受到更为复杂的有机粉尘的污染。高浓度真菌污染所引起的职业性变态反应性肺泡炎等免疫性肺疾病受到越来越广泛的关注。其基本病理特征是肺间质炎性细胞浸润和肉芽肿形成。但目前该病发病机制尚不十分清楚。前期研究表明调节性T细胞（Treg）通过调控Th免疫应答发挥其对变态反应性肺泡炎的免疫抑制作用。最新研究进展发现调节性B细胞（Breg）参与调控多种炎症性疾病的免疫机制，它可能通过分泌IL-10影响巨噬细胞、Treg活性，进而对炎症的Th免疫应答及其调控发挥免疫调节作用。但Breg对变态反应性肺泡炎调控机制尚未明确。本实验拟以真菌细胞壁主要成分1-3-β-葡聚糖所致的小鼠肺部炎症为模型，从细胞、分子水平探讨IL-10及Breg对Th免疫应答的启动、类型及其调控过程中的相关效应机制。旨在为职业性免疫性肺疾病的预防和控制提供新的理论依据。

随着现代工农业生产的不断发展，职业环境中暴露的有机粉尘种类越来越复杂，其中高浓度真菌污染尤为常见。1,3-β-Glucan作为真菌细胞壁的主要结构成分，是公认的职业环境中真菌暴露的生物标志物。吸入被真菌污染的有机粉尘而引起的以肺组织炎性细胞浸润和肉芽肿形成为基本病理特征的疾病，称为职业性变态反应性肺泡炎。目前该病发病机制尚不十分清楚。利用1,3-β-葡聚糖研究职业性变态反应性肺泡炎的免疫调控机制具有重要的实际意义。..研究显示，1,3-β-Glucan暴露可引起肺组织发生多种免疫应答，且变态反应性肺泡炎的发生发展存在多种Th免疫应答的相互转化与平衡。前期结果提示，调节性T细胞（Treg）通过调控Th免疫应答发挥对变态反应性肺泡炎的免疫抑制作用。最新进展发现调节性B细胞（Breg）参与调控多种炎症性疾病的免疫学发病机制，它可能通过分泌IL-10影响巨噬细胞、Treg，进而对炎症的Th免疫应答及其调控发挥免疫调节作用。但Breg对变态反应性肺泡炎调控机制尚未明确。..本研究以真菌细胞壁主要成分1-3-β-glucan所致的小鼠肺部炎症为模型，从细胞、蛋白、基因水平探讨Breg对Th免疫应答的调控机制及其调控过程中的相关效应机制。结果表明，利用抗CD22单克隆抗体腹腔注射可有效的抑制glucan暴露后小鼠体内Breg细胞的增加。肺组织病理学检测表明，CD22处理组小鼠暴露于1,3-β-Glucan后，其肺组织炎症反应更为剧烈，多种类型的炎性细胞浸润增加，促炎性细胞分子的水平升高。Breg不足显著促进1,3-β-Glucan暴露后小鼠肺组织多种Th应答的发生。进一步研究Breg对Th免疫应答的作用机制发现，CD22处理组小鼠Treg显著降低，而Treg正是直接对Th应答发挥调控作用的T细胞亚群；与此同时，抑制性细胞因子IL-10也显著降低，表明IL-10是Breg发挥免疫调控功能的重要介质。为探讨Breg与Treg的相互作用关系，本研究同时利用CD25单克隆抗体，分别于glucan暴露前、后消除Treg，发现仅当于暴露前消除Treg，才能显著抑制Breg细胞的增加。..综上所述，Breg细胞通过分泌IL-10及影响Treg调控1,3-β-Glucan诱导的肺组织Th免疫应答，进而发挥其对肺部炎症的免疫抑制作用。本研究旨在为职业性免疫性肺疾病的预防和控制提供新的理论依据。

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