Uveal melanoma expression of indoleamine 2,3-deoxygenase: Establishment of an immune privileged environment by tryptophan depletion
Uveal melanoma expression of indoleamine 2,3-deoxygenase: Establishment of an immune privileged environment by tryptophan depletion
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DOI：
10.1016/j.exer.2007.07.014
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发表时间：
2007-11-01
影响因子：
3.4
通讯作者：
Niederkorn, Jerry Y.
中科院分区：
文献类型：
--
作者：
Chen, Peter W.;Mellon, Jessamee K.;Niederkorn, Jerry Y.
吲哚胺 2,3-双加氧酶 (IDO) 催化色氨酸的降解，色氨酸是淋巴细胞活化和增殖所需的必需氨基酸。许多肿瘤表达 IDO，这意味着它是逃避 T 细胞介导的免疫攻击并建立免疫抑制肿瘤微环境的机制。本研究的目的是确定原发性和转移性葡萄膜黑色素瘤是否表达 IDO 基因以及葡萄膜黑色素瘤细胞是否可以消耗色氨酸。通过使用 IDO 特异性抗体进行免疫组织染色来测定来自荷瘤眼的原发性葡萄膜黑色素瘤和转移性葡萄膜黑色素瘤肝组织中 IDO 的原位表达。逆转录 PCR 用于评估原发性和转移性葡萄膜黑色素瘤细胞系的 IDO 基因转录。 IDO 蛋白表达通过葡萄膜黑色素瘤细胞蛋白裂解物的蛋白质印迹测定。通过测量葡萄膜黑色素瘤培养物上清液中犬尿氨酸（色氨酸降解产生的产物）的存在来评估 IDO 催化活性。来自肿瘤跳动的眼睛的原发性葡萄膜黑色素瘤和来自肝脏的转移性葡萄膜黑色素瘤原位不表达IDO。 IDO 在原发性或转移性葡萄膜黑色素瘤细胞系中均不组成型表达。然而，用干扰素-γ (IFN-γ) 刺激原发性和转移性葡萄膜黑色素瘤细胞培养物普遍上调 IDO 基因和蛋白质表达。来自IFN-γ处理的原代和转移性葡萄膜黑色素瘤细胞培养物的培养物上清液含有升高水平的犬尿氨酸。添加 IDO 抑制剂 1-甲基 DL-色氨酸显着降低了 IFN-γ 处理的葡萄膜黑色素瘤细胞培养物中的犬尿氨酸水平。这项研究的结果表明，原发性和转移性葡萄膜黑色素瘤诱导的 IFN-γ IDO 上调可能会产生局部免疫特权微环境，以促进逃避 T 细胞介导的免疫监视。 (C) 2007 Elsevier Ltd. 保留所有权利。
The enzyme indoleamine 2,3-dioxygenase (IDO) catalyzes degradation of tryptophan, an essential amino acid required for lymphocyte activation and proliferation. Many tumors express IDO which implies that it acts as a mechanism to evade T cell-mediated immune attack, and also to establish an immunosuppressive tumor microenvironment. The purpose of this study was to determine whether primary and metastatic uveal melanoma expressed the IDO gene and whether uveal melanoma cells could deplete tryptophan. In situ expression of IDO in primary uveal melanoma from tumor bearing eyes and metastatic uveal melanoma liver tissues was determined by immunohistostaining with IDO-specific antibody. Reverse transcription PCR was used to assess IDO gene transcription by primary and metastatic uveal melanoma cell lines. IDO protein expression was determined by Western blot of uveal melanoma cell protein lysate. IDO catalytic activity was assessed by measuring the presence of kynurenine, a product generated by tryptophan degradation, in uveal melanoma culture supernatants. Primary uveal melanoma from tumor-beating eyes and metastatic uveal melanoma from the liver did not express IDO in situ. IDO was not constitutively expressed in either primary or metastatic uveal melanoma cell lines. However, stimulation of primary and metastatic uveal melanoma cell cultures with interferon-gamma (IFN-gamma) universally upregulated both IDO gene and protein expression. Culture supernatants from IFN-gamma treated primary and metastatic uveal melanoma cell cultures contained elevated levels of kynurenine. Addition of the IDO inhibitor 1-methyl DL-tryptophan significantly diminished kynurenine levels in IFN-gamma treated uveal melanoma cell cultures. The results from this study suggest that IFN-gamma inducible IDO upregulation by primary and metastatic uveal melanoma may generate a local immune privileged microenvironment to promote escape from T cell-mediated immune surveillance. (C) 2007 Elsevier Ltd. All rights reserved.