Department of Dermatology, Ghent University Hospital, Ghent, Belgium.
Cancer Research Institute Ghent, Ghent, Belgium.
Front Immunol. 2020 Sep 24;11:531491. doi: 10.3389/fimmu.2020.531491. eCollection 2020.
Indoleamine 2,3-dioxygenase 1 (IDO1) is a cytosolic haem-containing enzyme involved in the degradation of tryptophan to kynurenine. Although initially thought to be solely implicated in the modulation of innate immune responses during infection, subsequent discoveries demonstrated IDO1 as a mechanism of acquired immune tolerance. In cancer, IDO1 expression/activity has been observed in tumor cells as well as in the tumor-surrounding stroma, which is composed of endothelial cells, immune cells, fibroblasts, and mesenchymal cells. IDO1 expression/activity has also been reported in the peripheral blood. This manuscript reviews available data on IDO1 expression, mechanisms of its induction, and its function in cancer for each of these compartments. In-depth study of the biological function of IDO1 according to the expressing (tumor) cell can help to understand if and when IDO1 inhibition can play a role in cancer therapy.
吲哚胺 2,3-双加氧酶 1（IDO1）是一种胞质血红素酶，参与色氨酸降解为犬尿氨酸。虽然最初认为 IDO1 仅参与感染期间固有免疫反应的调节，但随后的发现表明 IDO1 是获得性免疫耐受的一种机制。在癌症中，IDO1 的表达/活性不仅在肿瘤细胞中，而且在由内皮细胞、免疫细胞、成纤维细胞和间充质细胞组成的肿瘤周围基质中也有观察到。IDO1 的表达/活性也已在外周血中报道。本文综述了 IDO1 在这些部位的表达、诱导机制及其在癌症中的功能的现有数据。根据表达（肿瘤）细胞深入研究 IDO1 的生物学功能，可以帮助了解 IDO1 抑制是否以及何时可以在癌症治疗中发挥作用。
