探討介白質10基因在治療氣喘動物模式及誘發調節性 T 細胞之能力

Study on IL-10 gene in the therapeutic effect of murine model of asthma and the induction potential of regulatory T cells

傅麒玲(Chi-Ling Fu)

指導教授 ： 江伯倫

國立臺灣大學/醫學院/免疫學研究所/博士(2006年)

https://doi.org/10.6342/NTU.2006.02705

摘要

過敏性氣喘肇因於不當的Th2 反應，過敏原專一性 Th2 細胞失控地大量的製造細胞激素，引發肺部發炎反應，嗜酸性白血球聚集，呼吸道黏液大量分泌，氣管劇烈收縮等氣喘症狀。 因此，藉由免疫調節性細胞激素的作用達成抑制過度的 Th2 發炎反應應是合理的治療策略。目前已知 Th1 細胞激素(例如︰ IL-12) 和免疫抑制型細胞激素(例如︰ TGF-β 和 IL-10)，都具有降低 Th2 反應並且在調節肺部發炎反應上扮演重要角色。 因此，在本論文中，我們在同一個氣喘動物模式的實驗中，應用四種不同細胞激素(IL-12, IL-10, TGF-β and IL-4) 的DNA 基因質體分別在不同的過敏老鼠身上觀察其對治療氣喘的功效。我們的結果顯示，這些抑制發炎型的細胞激素，特別是 IL-10，可以有效抑制呼吸道的發炎反應。並且，我們也證明這種抑制療效與所給予的細胞激素 DNA 載體的劑量是正相關的。因此，為了 IL-10 基因的表現量與作用時間可以增加，我們進一步的用重組腺病毒載體取代 DNA 質體去評估 IL-10 的抑制效果。如我們所預期，在呼吸道區域表現的 IL-10 是一個可直接抑制過度發炎反應的方法。 然而，更好的治療方法應該是設法增進免疫調節功能去調控 Th2 反應進而能完全治癒過敏性氣喘。 由於，樹突細胞在啟動發炎反應及影響 T 細胞反應發展方向上扮演了舉足輕重的角色; 因此，調控樹突細胞功能會是一個極有潛力的治療策略。於是，接下來我們就藉由DC-IL-10 與 na?ve DO11.10 CD4+ T 細胞的共同培養實驗來評估所培養出來的細胞株之功能分析。結果證明此類細胞株具有類似調節性 T 細胞的功能。總結實驗結果說明了，抑制發炎型的細胞激素 IL-10，不只可以應用在發炎反應部位直接抑制發炎現象，也可以藉由 IL-10 基因改造後的DC 來達成調控免疫反應的治療策略。

關鍵字

氣喘 ； 介白質10 ； 基因治療 ； 調節性 T 細胞 ； 樹突細胞

並列摘要

Allergic asthma strongly correlates with airway inflammation caused by the unregulated production of cytokines secreted by allergen-specific type-2 T helper (Th2) cells. The inappropriate Th2 response causes airway eosinophilic inflammation, mucus hypersecretion and airway hyperreactivity (AHR) result in the symptoms of asthma. The logical resolution of inflammation in the lung occurs through the inhibition of exaggerated Th2-mediated responses by immuno-regulatory cytokines. Both Th1-relatived cytokines, such as IL-12 , and immunosuppressive cytokines, including TGF-β and IL-10, are the candidate cytokines for the treatment of allergic diseases as they downregulate Th2 responses. In current study, we had compared the effect of several cytokines (IL-12, IL-10, TGF-β and IL-4) simultaneously on disease development in a murine model of asthma. Our data demonstrated that anti- inflammatory cytokines, particularly IL-10, have the therapeutic potential for the alleviation of airway inflammation in the asthma model in a dose-dependent manner. Furthermore, in order to achieve high local concentration of IL-10, we used IL-10-expressing adenovirus (Ad-IL-10) to elucidate the therapeutic effect of prolonged homologous IL-10 administration on airway inflammation. As our respect, localized expression of IL-10 may provide a more direct therapeutic approach for diseases of exaggerated proinflammation. However, a more attracting strategy is to enhance immune regulation, which can suppress or modulate Th2 response and cure allergic disease finally. Dendritic cells (DCs) play a crucial role in directing T helper cells differentiation and could be a good candidate of this therapeutic approach. Thus, we had examined whether Ad-IL-10 infected DCs (DC-IL-10) have the potential to induce the differentiation of Tr1-like cells by in vitro repetitive stimulation of na?ve DO11.10 CD4+ T cells with DC-IL-10 and suggest their therapeutic use. Taken together, these results suggested that application of immune-suppressive cytokine, such as IL-10, not only can suppress airway inflammation locally, but also has potential to modulate immune response by genetically modified DCs.

並列關鍵字

asthma ； interleukin-10 ； gene therapy ； regulatory T cells ； dendritic cells

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