2015年6月18日訊 /生物谷BIOON/ --近日,來自美國的研究人員在著名國際學術期刊Cell在線發表了一項最新研究進展,他們發現內質網應激應答因子XBP1能夠通過調節脂質代謝影響DC細胞功能,抑制T細胞抗腫瘤免疫,促進腫瘤進展,為腫瘤免疫治療的發展提供了一個重要線索。
本文亮點:
●腫瘤微環境中的DC細胞存在ER應激和IRE1a/XBP1激活
●DC細胞內的XBP1能夠驅動原位和轉移性卵巢癌進展
●XBP1能夠調節tDC細胞的脂質代謝和抗原遞呈
●在tDC細胞中沉默XBP1能夠增強T細胞抗腫瘤免疫延長宿主生存時間
樹突狀細胞(DC)在起始和維持T細胞依賴性抗腫瘤免疫中發揮著重要作用。但腫瘤常通過損傷正常DC細胞功能削弱免疫系統的控制。內質網應激應答因子XBP1能夠直接促進腫瘤細胞生長,但XBP1是否具有調控宿主抗腫瘤免疫應答的作用仍不清楚。
在該項研究中,研究人員發現在腫瘤相關DC細胞中組成型激活的XBP1能夠通過阻斷抗腫瘤免疫驅動乳腺癌進展。XBP1的激活以脂質過氧化反應產生的副產物為動力,誘導tDC細胞中甘油三酯的合成模式發生改變,導致tDC細胞中脂質異常積累,抑制了tDC細胞對抗腫瘤T細胞功能發揮的促進作用。隨後,研究人員在DC細胞中特異性刪除XBP1或通過納米顆粒介導的基因沉默方法在tDC細胞中特異性沉默XBP1表達,結果發現tDC細胞的免疫刺激活性得到恢復,同時也通過產生具有保護性的I型抗腫瘤免疫應答延長了宿主的生存時間。
總得來說,這項研究表明在DC細胞中靶向ER應激應答反應可以抑制腫瘤生長,增強抗腫瘤免疫,這一發現為腫瘤免疫治療提供了一種重要的潛在方法,具有重要意義。(生物谷Bioon.com)
ER Stress Sensor XBP1 Controls Anti-tumor Immunity by Disrupting Dendritic Cell Homeostasis
Juan R. Cubillos-Ruiz, Pedro C. Silberman, Melanie R. Rutkowski, Sahil Chopra, Alfredo Perales-Puchalt, Minkyung Song, Sheng Zhang, Sarah E. Bettigole, Divya Gupta, Kevin Holcomb, Lora H. Ellenson, Thomas Caputo, Ann-Hwee Lee, Jose R. Conejo-Garcia, Laurie H. Glimcher
Dendritic cells (DCs) are required to initiate and sustain T cell-dependent anti-cancer immunity. However, tumors often evade immune control by crippling normal DC function. The endoplasmic reticulum (ER) stress response factor XBP1 promotes intrinsic tumor growth directly, but whether it also regulates the host anti-tumor immune response is not known. Here we show that constitutive activation of XBP1 in tumor-associated DCs (tDCs) drives ovarian cancer (OvCa) progression by blunting anti-tumor immunity. XBP1 activation, fueled by lipid peroxidation byproducts, induced a triglyceride biosynthetic program in tDCs leading to abnormal lipid accumulation and subsequent inhibition of tDC capacity to support anti-tumor T cells. Accordingly, DC-specific XBP1 deletion or selective nanoparticle-mediated XBP1 silencing in tDCs restored their immunostimulatory activity in situ and extended survival by evoking protective type 1 anti-tumor responses. Targeting the ER stress response should concomitantly inhibit tumor growth and enhance anti-cancer immunity, thus offering a unique approach to cancer immunotherapy.