臺灣博碩士論文加值系統

過敏性的氣喘是由第二類輔助型T細胞 (T helper type 2 (Th2))所介導調控進而產生的致敏性疾病。此疾病在吸入過敏原後支氣管會有大量的黏液分泌產生且呼吸道也會有發炎的症狀，同時也伴隨著許多嗜酸性細胞的浸潤。然而，雖然Th2 細胞在支氣管氣喘中的作用及功能已經被許多的研究指出，可是對於吸入性的過敏原是如何啟動Th2的免疫反應的機轉卻尚未明瞭。
樹突狀細胞是專業的抗原呈現細胞，它在連結先天性免疫及後天性免疫中扮演 重要的角色。被活化(成熟)的樹突狀細胞的功能主要可以促使naïve T 細胞的分化，並且也確立T細胞的記憶性和周邊耐受性。而Toll-like receptors (TLRs) 在調控樹突狀細胞功能上的成熟也扮演著不可或缺的角色。根據我們先前的研究指出，在吸入(抗原)雞卵蛋白(ovalbumin (OVA))並伴隨著些許劑量的LPS時，藉由TLR4傳遞訊息，此時會引起過敏性的Th2免疫反應。不過在沒有微生物的致病(機轉)結構時卻不會引起任何的免疫反應。而且，有趣的是，在誘發Th2的免疫反應或支氣管發炎時是需要低濃度的LPS參與其中，而相反的是高濃度的LPS卻會誘發Th1的免疫反應。
因此，我們想要知道在給予不同劑量的LPS時，雖然它們都經由TLR4這條訊息傳遞途徑，同樣的刺激物走同一條路徑，為何最終卻會引起不同的免疫反應？而根據之前的研究指出，我們知道樹突狀細胞上的Notch ligand Jagged-1和 Delta-Like 4會被不同濃度的LPS所調控。因此，這有可能就是影響Th細胞分化的命運。

Atopic asthma is a T helper type 2 (Th2) cell mediated disorder in which sensitized individuals develop eosinophilic airway inflammation and mucus hypersecretion in response to inhaled aeroallergens. Yet, despite the known role of Th2 cells in asthma, the factors governing the initiation of a Th2 response to aeroallergens are not well understood.
Dendritic cells are potent antigen presenting cells which link innate and adaptive immune responses. Activated DCs can polarize naïve T cells and have a central role in the establishment of T cell memory and peripheral tolerance. Toll-like receptors (TLRs) are believed to play a pivotal role in regulating dendritic cells (DCs) functional maturation. Our previous research has generated data that inhaled ovalbumin (OVA) requires low dose lipopolysaccharide (LPS) signaling through TLR4 to induce allergic Th2 responses. In the absence of this microbial motif, OVA does not induce an immune response. Interestingly, whereas low concentrations of LPS are required for Th2 responses and Th2 driven airway inflammation, higher concentrations of LPS induces Th1 response.
We question: How might signaling through a single receptor lead to the induction of two distinct immune responses? Here we identified that Notch ligand Jagged-1 and Delta-4 on DCs are differential regulated by different dose of LPS (low and high respectively) that in turn influence the fate of Th cell differentiation.

目錄
目錄 I
英文摘要 (Abstract in English) II
中文摘要 (Abstract in Chinese) III
圖目錄 IV
縮寫表 V
第一章 序論 (Introduction) 1
第一節 過敏性氣喘 (Asthma) 1
第二節 輔助型T細胞 (T helper cell) 3
第三節 抗原呈現細胞 (Antigen presenting cells) 及
樹突狀細胞 (Dendritic cells) 5
第四節 Toll-like receptor 4 (TLR4) and LPS 6
第五節 Notch ligand (Jagged1, Delta-like 4) 9
第六節 研究動機 12
第二章 實驗材料及方法 (Materials and Methods) 13
第一節 實驗材料 13
第二節 實驗方法 22
第三章 實驗結果 (Result) 29
第四章 討論 (Discussion) 34
第五章 結論 37
第六章 圖表 38
第七章 參考文獻 (Reference) 46

1. Eisenbarth, S., et al., Lipopolysaccharide-enhanced, toll-like receptor 4–dependent T helper cell type 2 responses to inhaled antigen. J. Exp. Med, 2002. 196: 1645–1651.
2. Akinbami, L. J.,et al., Trends in childhood asthma: Prevalence, health care utilization, and mortality. Pediatrics, 2002.110: 315–323.
3. Hirata, H., et al., Molecular immunology. 2008.45:2734-2742
4. Zhu, J., et al., CD4 T cells: fates, functions, and faults. Blood. 2008. 112:1557–1569.
5. Banchereau, J., et al., Immunobiology of dendritic cells. Annu Rev Immunol 2000.18:767–811.
6. Reise, S.C., et al., Dendritic cells as sensors of infection. Immunity. 2001. 14:495–498.
7. Reise, S.C., et al., Dendritic cells in a mature age. Nat Rev Immunol 2006.6:476–483.
8. Akira, S., et al., Toll-like receptors: critical proteins linking innate and acquired immunity. Nat. Immunol. 2001. 2: 675–680
9. Medzhitov, R., et al., A human homologue of the Drosophila Toll protein signals activation of adaptive immunity. Nature. 1997.388: 394–397
10. Akira, S., et al., Pathogen recognition and innate immunity. Cell. 2006. 124:783-801
11. Kagan, J.C., et al., Phosphoinositide-mediated adaptor recruitment controls Toll-like receptor signaling. Cell. 2006. 125:943-955.
12. Tanimura, N., et al., Roles of LPS-dependent interaction and relocation of TLR4 and TRAM in TRIF-signaling. Biochem. Biophys. Res. Commun. 2008. 368:94-99.
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13. Bray, S. J., et al., Notch signaling: a simple pathway become complex. Nature Rev. Mol. Cell Biol. 2006. 7:678-689.
14. Artavanis,T. S., et al., Notch signaling: cell fate control and signal integration in development. Science. 1999.284:770-776.
15. D’Souza, B., et al., The many facets of Notch ligands. Oncogene. 2008.27: 5148-5167.
16. Worsley, A. G., et al., Dendritic cell expression of the Notch ligand Jagged2 is not essential for Th2 response induction in vivo. Eur. J, Immunol. 2008.38:1043-1049.
17. Tu, L., et al., Notch signaling is an important regulator of type 2 immunity. J. Exp. Med. 2005. 202:1037-1042.
18. Derk, A., et al., The different faces of Notch in T-helper-cell differentiation. Nature Rev. Immunol. 2009. 9:116-124.
19. Fang, T.C., et al., Notch directly regulates Gata3 expression during T helper 2 cell differentiation. Immunity. 2007.27:100-110.
20. Liotta, F., et al., Human immature myeloid dendritic cell trigger a TH2-polarizing program via Jagged-1/Notch interaction. J. Allergy Clin. Immunol. 2008.121:1000-1005.
21. Kiwamoto, T., et al., Transcription factors T-bet and GATA-3 regulate development of airway remodeling. American Journal of Respiratory and Critical Care Medicine. 2006. 174:142-151.
22. Villagra,A., et al., Histone deacetylase and the immunological network: implications in cancer and inflammation. Oncogene. 2010 .29:157-173.
23. Gao, L., et al., Cloning and functional characterization of HDAC11, a novel member of human histone deacetylase family. J Biol Chem. 2002. 277:25748-25755.
24. Mann, BS., et al., Vorinostat for treatment of cutaneous manifestations of
48
advanced primary cutaneous T-cell lymphoma. Clin Cancer Res. 2007. 13:2318-2322.