Abstract
摘要:近幾十年來氣喘等過敏免疫疾病罹患率逐年增加,因此如何藉由飲食因子調節免疫功能的研究,逐漸成為重要的研究議題。本研究欲利用口服給予過敏原以降低過敏原專一性之免疫反應,稱為「口服耐受性(oral tolerance)」的理論,探討經口攝入大量過敏原蛋白質時,對該過敏原的過敏免疫反應,包括呼吸道發炎反應和免疫調節傾向的影響、影響機轉、以及可能緩過敏免疫疾病的可行性。本研究計畫「營養素對口服耐受性調節過敏免疫反應的影響探討」為三年計畫,分別進行以下實驗:
I.攝食塵蟎蛋白對致敏小鼠過敏免疫反應的影響:
以轉型酵母菌(Pichia pastoris)生產Dp2重組蛋白(recombinant Dp2, 簡稱rDp2),將此蛋白致敏BALB/c 小鼠及氣管內刺激來建立氣喘模式,探討給予致敏小鼠口服不同劑量Dp2,對呼吸道發炎反應、T細胞調節及腸道免疫反應之影響。
II.口服耐受性對腸道免疫細胞的基因表現的影響:為探討當同樣過敏原經由腸道途徑進入所產生口服耐受性,如何影響腸道免疫細胞的基因表現,與其表現的時程,由第一年建立的致敏模式,分別在口服大量過敏後、追加三次過敏原腹腔致敏後、和過敏原吸入三個時程犧牲小鼠,以微陣列(microarray)分析腸道細胞基因表現與其變化。
III.促進口服耐受性調節過敏免疫作用的營養素探討:在了解口服耐受性對腸道免疫細胞的哪些基因表現有顯著的影響之後,第三年計畫將進一步研究營養素的添加是否可更有效促進口服耐受性的效果而達到抑制過敏免疫反應。因此,我們將利用目前已知具有調控免疫反應的營養素,例如:鋅、維生素A、D和E或維生素C和葉酸、EPA和DHA等,先利用分離自腸道和脾臟的免疫細胞進行細胞培養的研究篩選,是否有任何營養素可以促進第二年計畫中所影響的基因表現,利用real-time PCR的方法來測定調節性T細胞相關的基因例如CRIP3、CD226、Foxp3、TGF-等。再進行口服耐受性的動物模式,探討該營養素的添加是否能夠更進一步促進口服耐受性。
Abstract: The frequency of allergic diseases such as asthma and allergic rhinitis has increased rapidly during the past decade; however, the exact mechanisms have still not been established. Oral tolerance has been found to decrease antigen-specific immune responses in several diseases. In this study, we like to apply the method of oral tolerance for the treatment of allergic asthma. Several mechanisms such as regulatory T cells or T cell anergy have been addressed for accounting for the effect of oral tolerance. We like to explore the possible nutrients on enhancing oral tolerance to decrease allergen-specific immune response.
This project [The effect of nutrients on enhancing oral tolerance for immune regulation of allergic disease] will be carried in three years, detailed as follow:
I. The effect of oral feeding mite allergen on the immune response:We like to feed the mice with Pichia pastoris-derived recombinant Dp2 (rDp2) in a murine model of asthma induced by rDp2 allergen. The rDp2-sensitized mice will be fed with different doses of rDp2 allergen and followed for their airway inflammation, cell infiltration and also hyperresponsiveness. In addition, we also like to investigate the function and cytokine profiles of T cells in mice of oral tolerance.
II. The effect of oral tolerance on the gene expression of intestinal Peyer’s patch: We like to study the changes of the expressed genes of Peyer’s patch in mice induced oral tolerance by feeding with the rDp2 allergen. The mice will be fed with adequate dose of rDp2 allergen followed by intraperitoneal injection of rDp2 antigen and Peyer’s patches will be isolated for the analysis of gene expression with the method of microarray.
III. Enhancing effect of nutrients on oral tolerance: Since gene can be regulated by nutrients, we also like to explore the possible nutrients, such as zinc, vitamin A, D, E, C or folate, EPA and DHA, for enhancing oral tolerance for the treatment of allergic diseases. All these nutrients have been found to have immuno-modulatory effect in the previous studies. We like to establish an in vitro method to screen the nutrients, which can induce higher expression of genes, such as CRIP3, CD226, Foxp-3 or TGF- identified in 2nd year’s project. The effective nutrients will be further confirmed its oral tolerance enhancing effect with in vivo animal model.
We believe the project here will help in understanding the effect and also mechanisms of oral tolerance in decreasing antigen-specific immune response. The information here might shed light on further applying the approach of oral tolerance for the treatment of allergic diseases in the future.
Keyword(s)
口服耐受性
塵蟎
塵蟎
蛋白
氣喘
腸道免疫
oral tolerance
mite
mite allergens
asthma
mucosal immune response