https://scholars.lib.ntu.edu.tw/handle/123456789/194402
標題: | 以單分子IL-12核酸載體在過敏性氣喘的動物模式中進行基因治療 | 作者: | 蔡銘哲 | 公開日期: | 1999 | 出版社: | 臺北市:國立臺灣大學醫學院小兒科 | 摘要: | 過敏性氣喘的特徵是臨床上表現呼吸 道過度反應(hyperresponsiveness)及肺 部呈慢性發炎的病理變化。這組織病理 變化主要為呼吸道黏膜有嗜酸性白血 球,肥胖細胞及單核球浸潤,活化的輔 助型T 細胞增加。這些變化都與第二型 輔助T 細胞活化有密切關係。針對Th2 vs Th1 理論,許多新的免疫療法就被開 發出來。非過敏原特異性的免疫療法 中,就包括了以interleukin 12 來誘發細 胞免疫反應,增進Th1 細胞激素的產 生,尤其是IFN-g,並降低Th2 的反應。 已有動物實驗,證明以腹腔內注射、 或以霧化器吸入(nebulization) IL-12 能 減輕過敏原引起的呼吸道敏感及發炎反 應。它可以減少實驗動物肺泡沖洗液中 嗜酸性白血球的量,減少肺泡沖洗液中 IL-4、IL-5 的量;而增加interferon- 的 量。惟注射、或以霧化器吸入IL-12 維 持時間短暫,須重複注射、或吸入給予 方能奏效,基因治療恰可彌補這一缺 點。 本計畫的目標是,建立以ovalbumin 致敏的動物模式,以便將來以之作為研 究IL-12 DNA 對氣道敏感狀態長期影 響。 我們成功地在BALB/c 老鼠上建立一 個Th2 為主的發炎反應。在以intraperitoneal 加上 intra-tracheal 合併致敏 模式中,在2nd challenge 後24 小時,實 驗動物的肺泡沖洗液中,可以出現 interleukin 5 這個Th2 的cytokine, eosinophil count 也會上升。血液中的 OVA-specific IgE 也可以偵測到。 經由不同路徑將lux-pCMV 核酸載體 給予實驗動物,利用luciferase assay 的 方法,經由偵測reporter gene 在黏膜組 織細胞中的表現,評估gene therapy 之 最佳給予路徑的實驗中,我們可以在 intravenous route 組的動物中,發現lung 及 liver 有表現。可是intratracheal route 組,卻無法偵測到其表現。顯示以將老 鼠的舌頭拉出,讓動物吸入DNA 的方 法,仍須在精進。用nebulization 方法 deliver cationic lipid:DNA complex 是個 值得嘗試的方法。Size 較小的chamber, 或利用plethysmography的main chamber 的inlet 為之,也許能更經濟且有效率。 luciferase 的活性測定過程中,如、老鼠 肺臟組織的研磨取樣方法也應再改進。 Bronchial asthma is characterized by chronic inflammatory process in the airways, which translates to bronchial hyer-responsiveness clinically. The preferential activation of type 2 helper (Th2) cells play a key role in the pathogenesis. Hence the treatment modality aimed at reversing the Th2 response has been eagerly sought for. Interleukin 12 (IL-12), a heterdimeric cytokine, has been demonstrated to have 2 beneficial effect in animal models of atopic asthma in terms of its effect to inhibit antigen-induced airway hyperresponsiveness, inflammation and Th2 cytokine expression. Its potential therapeutic use, however, is limited by the short-lived effect of injected cytokine. Therefore we try to establish an animal model of atopic asthma on which efficacy of IL-12 plasmid gene therapy can be tested. In this year’s project, we succeed in establishing an animal model of atopic asthma. The combination of intraperitoneal and intra-tracheal route of OVA administration makes a good model of Th2 inflammation in the lung. The cytokine profile in broncho-alveolar lavage (BAL) was of Th2 in pattern. There was eosinophilia in the BAL. The serum IgE specific to OVA can be demonstrated in animals. Unfortunately we were not able to perform pulmonary function test in this model since the only pulmonary function machine in our facility has too much dead space for such a small animal to be tested. On the other hand, we also intended to determine to expression of introduced plasmid in order to define the best route of DNA delivery. The reporter gene expression could be detected in the lung and spleen in the IV group. However, the intratracheal route was unsuccessful in this experiment. The problem may lie in the technical difficulties per se or the methodology of detecting reporter gene’s expression. Delivery of plasmid DNA via nebulization is worth trying since it may be superior to intratracheal route in terms of fewer techniques required and more economic and efficient if smaller chamber is employed. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/22836 | 其他識別: | 882314B002220 | Rights: | 國立臺灣大學醫學院小兒科 |
顯示於: | 醫學系 |
檔案 | 描述 | 大小 | 格式 | |
---|---|---|---|---|
882314B002220.pdf | 32.76 kB | Adobe PDF | 檢視/開啟 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。