Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy.
Mol Med. 2012 Jul 18;18(1):834-42. doi: 10.2119/molmed.2012.00029.
Indoleamine 2,3-dioxygenase (IDO), a metabolic enzyme that catalyzes tryptophan conversion into kynurenines, is a crucial regulator of immunity. Altered IDO activity is often associated with pathology, including neoplasia and autoimmunity. IDO is highly expressed in dendritic cells (DCs) that exploit the enzyme's activity and the production of tryptophan catabolites to regulate immune responses by acting on several cell types, including T lymphocytes, of which they promote a regulatory phenotype. IDO also contains immunoreceptor tyrosine-based inhibitory motifs (ITIMs) that, once bound by distinct molecular partners, will either promote degradation or initiate signaling activity and self-maintenance of the enzyme. We here discuss how ITIM-dependent molecular events can affect the functional plasticity of IDO by modifying the protein half-life and its enzymic and nonenzymic functions.
吲哚胺 2,3-双加氧酶（IDO）是一种代谢酶，可催化色氨酸转化为犬尿氨酸，是免疫的重要调节剂。IDO 活性的改变通常与病理学有关，包括肿瘤和自身免疫。IDO 在树突状细胞（DC）中高度表达，这些细胞利用酶的活性和色氨酸代谢产物的产生来调节免疫反应，作用于包括 T 淋巴细胞在内的多种细胞类型，促进调节表型。IDO 还含有免疫受体酪氨酸基抑制基序（ITIM），一旦与特定的分子伴侣结合，就会促进酶的降解或启动信号转导活性和自我维持。我们在这里讨论了 ITIM 依赖性分子事件如何通过改变蛋白质半衰期及其酶和非酶功能来影响 IDO 的功能可塑性。
