- 學位論文
建立異位性皮膚炎小鼠模式並探討益生菌在此疾病模式的免疫調控機制
Establishment of atopic dermatitis in mouse model and investigation of the immune modulatory effect of probiotics in this model
摘要
異位性皮膚炎是一種過敏性皮膚病，其中環境過敏原是重要致病原因之一。當過敏原侵入皮膚引發敏性疾病時，會使輔助型T細胞，活化分化為第2型輔助性T細胞 (Th2)。過去文獻使用OVA誘導異位性皮膚炎的小鼠模型，作為研究異位性皮膚炎的疾病模式。最近許多研究文獻報導指出在過敏性疾病，益生菌可以透過調控體內免疫功能，使免疫功能平衡，進而緩解過敏症狀。此外，服用納豆菌會增加或安定原本腸內的有益菌，但是納豆菌在過敏疾病的研究極少。在本篇研究，我們利用過去文獻方法建立異位性皮膚炎小鼠模型，並且分別利用含有四種益生菌: Bifidobacterium. bifidum 、Bifidobacterium longum 、Lactobacillus plantarum、Lactobacillus rhamnosus的益生菌混合試劑和納豆菌 (Bacillus natto Sawamura)餵食小鼠模型，探討益生菌混合試劑和納豆菌對於異位性皮膚炎的療效和體內免疫調節功能的變化。我們參考先前文獻，利用OVA成功建立異位性皮膚炎小鼠模型，不論在皮膚外觀觀察、皮膚組織切片、侵入發炎細胞計數、血清中IgE抗體濃度、Th2、Th17細胞激素變化分析，處理OVA誘導異位性皮膚炎小鼠和處理PBS正常小鼠相比，有明顯發炎現象。過去許多文獻研究發現，益生菌在體內會誘導增加Th1細胞激素表現量和輔助性T細胞數量，改善免疫功能不平衡所造成免疫失調現象，進而緩解過敏症狀。但是在我們研究，處理益生菌混合試劑和納豆菌組別的異位性皮膚炎小鼠在皮膚外觀觀察、皮膚組織切片、侵入發炎細胞計數、血清中IgE抗體濃度、Th2細胞激素變化分析與處理OVA但不餵食益生菌混合試劑和納豆菌異位性皮膚炎小鼠相比，並無明顯有改善發炎現象。以及進一步分析比較Th1細胞激素IFN-γ表現量和調節性T細胞轉錄因子FOXP3表現量，但也沒有明顯差異性。 由上述實驗結果所得結論，我們使用的益生菌混合試劑和納豆菌，在異位性皮膚炎小鼠的模式上，無法有效調控體內的免疫反應進而改善解緩異位性皮膚炎。
並列摘要
Atopic dermatitis (AD) is an allergic disease of skin and caused by environmental allergens. Differentiated type 2 helper T (Th2) cells arise while invasion of allergens in skin. A mouse model of atopic dermatitis, OVA-induced allergic skin, was investigated in previous study. Recently much researches reported that treatment of probiotics can modulate immune response and cause immunological homeostasis, even relieve allergy symptoms. However, administration of Bacillus natto increase and stabilize the normal flora resident in intestine although these related studies are rare. In this study we use the OVA-induced method to establish mouse model of AD, and feed mouse for mixed probiotics include Bifidobacterium bifidum, Bifidobacterium longum, Lactobacillus plantarum, and Lactobacillus rhamnosus or natto bacteria (Bacillus natto Sawamura) to investigate the therapeutic and immunological effects of mixed probiotic reagents or Bacillus natto in AD. We successfully established a mouse model of atopic dermatitis refer to previous study, and found that OVA-induced mice had much severe inflammatory response including the appearance of skin, increased invasive cell count in the skin, increased IgE concentration of serum, and the up-regulated Th2 related cytokine expression of splenocytes compared to the PBS-induced mice. Many studies had found that probiotics may increases the expression of Th1 cytokines and Treg cells in vivo, cause immunological homeostasis and even relieve allergy symptoms. However, in our study, treatment of mixed probiotics or Bacillus natto could not ameliorate inflammation including the appearance of the skin, invasive cell count in skin, IgE concentration of serum, and Th2 related cytokine expression compared to the mice of OVA-handling only. Further we analyzed the Th1 cytokine IFN-γ expression and regulatory T cells transcription factor FOXP3 expression and found there is no significant difference between these. Therefore, we use the mixed probiotic reagents and Bacillus natto in AD model, and cannot effectively modulate the immune response even to see any improvement of the disease.