CR3與Dectin-1透過與脂筏連結及活化Syk-JNK-AP-1訊息傳遞路徑機制共同合作引起巨噬細胞的細胞激素反應

CR3 and Dectin-1 Collaborate in Macrophage Cytokine Response through Association on Lipid Rafts and Activation of Syk-JNK-AP-1 Pathway

黃俊樺(Juin-Hua Huang)

指導教授 ： 伍安怡

國立臺灣大學/醫學院/免疫學研究所/博士(2015年)

https://doi.org/10.6342/NTU.2015.10681

摘要

真菌感染的發生率在過去近幾十年來不斷地增加，且威脅患者的生命。更進一步地了解真菌病原體與宿主細胞之間的交互作用，將有助於抗真菌治療新策略的開發。不同種類的模式辨識受體的合作作用引起的免疫反應之協同作用對於宿主抵禦入侵的病原體是很重要的。第三型補體受體及Dectin-1是先天性免疫細胞上主要用來辨識真菌的模式辨識受體，然而這兩個受體在抵禦真菌的免疫反應上的合作機制還尚未被釐清。在此研究中，我們利用組織胞漿菌能同時與第三型補體受體和Dectin-1交互作用的特性，以及利用專一性的顆粒性配體來探討第三型補體受體與Dectin-1在巨噬細胞細胞激素反應上的合作機制。經由使用高通量的微西方陣列技術（Micro-Western Array）、基因改造策略以及藥物抑制劑，我們證明第三型補體受體與Dectin-1能共同合作引起巨噬細胞產生腫瘤壞死因子及介白素-6反應，且此合作作用是透過匯集第三型補體受體與Dectin-1的下游訊息傳遞於Syk激酶，進而增強Syk-JNK-AP-1訊息途徑的活化所致。當巨噬細胞受到組織胞漿菌的刺激，第三型補體受體與Dectin-1會被召集到細胞膜上的脂筏形成聚集，並將脂筏當作平台促進第三型補體受體與Dectin-1引起的訊息活化及細胞激素反應的合作作用。此外，我們也利用小鼠全身性感染組織胞漿菌之實驗模式來研究第三型補體受體與Dectin-1在體內感染的合作現象。實驗結果顯示第三型補體受體與Dectin-1合作參與宿主抵禦組織胞漿菌感染，並且共同影響抗真菌之後天性免疫反應。我們的研究結果提供了第三型補體受體與Dectin-1兩種模式辨識受體間如何合作之分子機制，並證明第三型補體受體與Dectin-1的合作作用對於宿主抵禦真菌的重要性。

關鍵字

真菌感染 ； 受體合作 ； C型凝集素受體 ； Dectin-1 ； 第三型補體受體 ； 巨噬細胞 ； 組織胞漿菌 ； 訊號交互作用 ； 先天性抗真菌免疫 ； 促發炎細胞激素 ； 脂筏 ； 受體聚集 ； 後天性抗真菌免疫

並列摘要

The incidence of life-threatening fungal infections are increasing during the last decades. A better understanding of the interactions between fungal pathogen and its host cell is important to the development of new therapeutic strategies against fungal infections. Collaboration between heterogeneous pattern recognition receptors (PRRs) leading to synergistic coordination of immune response is important for the host to fight against invading pathogens. Complement receptor 3 (CR3) and Dectin-1 are major PRRs to detect fungi. However, crosstalk between these two receptors in antifungal immunity is largely undefined. Here we took advantage of Histoplasma capsulatum which is known to interact with both CR3 and Dectin-1 and specific particulate ligands to study the collaboration of CR3 and Dectin-1 in macrophage cytokine response. By employing Micro-Western Array (MWA), genetic approach, and pharmacological inhibitors, we demonstrated that CR3 and Dectin-1 act collaboratively to trigger macrophage TNF and IL-6 response through signaling integration at Syk kinase, allowing subsequent enhanced activation of Syk-JNK-AP-1 pathway. Upon engagement, CR3 and Dectin-1 colocalize and form clusters on lipid raft microdomains which serve as a platform facilitating their cooperation in signaling activation and cytokine production. Furthermore, in vivo studies showed that CR3 and Dectin-1 cooperatively participate in host defense against disseminated histoplasmosis and instruct adaptive immune response. Taken together, our findings define the molecular mechanisms underlying receptor crosstalk between CR3 and Dectin-1 and demonstrate the importance of their collaboration in host defense against fungal infection.

並列關鍵字

fungal infection ； receptor collaboration ； C-type lectin ； Dectin-1 ； complement receptor 3 ； macrophage ； Histoplasma capsulatum ； signaling crosstalk ； innate antifungal immunity ； pro-inflammatory cytokine ； lipid raft ； receptor clustering ； adaptive antifungal immunity

參考文獻

Abram, C.L., and Lowell, C.A. (2009). The ins and outs of leukocyte integrin signaling. Annu Rev Immunol 27, 339-362.

Ali, T., Kaitha, S., Mahmood, S., Ftesi, A., Stone, J., and Bronze, M.S. (2013). Clinical use of anti-TNF therapy and increased risk of infections. Drug Healthc Patient Saf 5, 79-99.

Allendoerfer, R., and Deepe, G.S., Jr. (1997). Intrapulmonary response to Histoplasma capsulatum in gamma interferon knockout mice. Infect Immun 65, 2564-2569.

Allendoerfer, R., and Deepe, G.S., Jr. (1998). Blockade of endogenous TNF-alpha exacerbates primary and secondary pulmonary histoplasmosis by differential mechanisms. J Immunol 160, 6072-6082.

Allendoerfer, R., and Deepe, G.S., Jr. (2000). Regulation of infection with Histoplasma capsulatum by TNFR1 and -2. J Immunol 165, 2657-2664.