PMID- 26269528 OWN - NLM STAT- MEDLINE DCOM- 20160525 LR - 20211108 IS - 2326-6074 (Electronic) IS - 2326-6066 (Linking) VI - 3 IP - 9 DP - 2015 Sep TI - Tumoral Immune Resistance Mediated by Enzymes That Degrade Tryptophan. PG - 978-85 LID - 10.1158/2326-6066.CIR-15-0095 [doi] AB - Cancer patients mount T-lymphocyte responses against antigens expressed selectively by their malignancy, but these responses often fail to control their disease, because tumors select mechanisms that allow them to resist immune destruction. Among the numerous resistance mechanisms that have been proposed, metabolic inhibition of T cells by tryptophan catabolism deserves particular attention, because of the frequent expression of tryptophan-degrading enzymes in human tumors, and because in vitro and in vivo studies have shown that their enzymatic activity can be readily blocked by pharmacologic inhibitors, thereby restoring T-cell-mediated tumor cell killing and paving the way to targeted therapeutic intervention. In view of recent observations, and taking into account the differences between human and mouse data that differ in several aspects, in this Cancer Immunology at the Crossroads article, we discuss the role of the three enzymes that have been proposed to control tryptophan catabolism in tumoral immune resistance: indoleamine 2,3-dioxygenase 1 (IDO1), tryptophan 2,3-dioxygenase (TDO), and indoleamine 2,3-dioxygenase 2 (IDO2). CI - (c)2015 American Association for Cancer Research. FAU - van Baren, Nicolas AU - van Baren N AD - Ludwig Institute for Cancer Research, Brussels, Belgium. de Duve Institute, Universite catholique de Louvain, Brussels, Belgium. FAU - Van den Eynde, Benoit J AU - Van den Eynde BJ AD - Ludwig Institute for Cancer Research, Brussels, Belgium. WELBIO (Walloon Excellence in Life Sciences and Biotechnology), Brussels, Belgium. de Duve Institute, Universite catholique de Louvain, Brussels, Belgium. benoit.vandeneynde@bru.licr.org. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PT - Review DEP - 20150812 PL - United States TA - Cancer Immunol Res JT - Cancer immunology research JID - 101614637 RN - 0 (IDO1 protein, human) RN - 0 (IDO2 protein, human) RN - 0 (Indoleamine-Pyrrole 2,3,-Dioxygenase) RN - 8DUH1N11BX (Tryptophan) RN - EC 1.13.11.11 (Tryptophan Oxygenase) SB - IM MH - Humans MH - Indoleamine-Pyrrole 2,3,-Dioxygenase/physiology MH - Lymphocytes, Tumor-Infiltrating/immunology MH - Neoplasms/enzymology/*immunology MH - Tryptophan/*metabolism MH - Tryptophan Oxygenase/physiology MH - Tumor Escape/*immunology EDAT- 2015/08/14 06:00 MHDA- 2016/05/26 06:00 CRDT- 2015/08/14 06:00 PHST- 2015/04/09 00:00 [received] PHST- 2015/06/03 00:00 [accepted] PHST- 2015/08/14 06:00 [entrez] PHST- 2015/08/14 06:00 [pubmed] PHST- 2016/05/26 06:00 [medline] AID - 2326-6066.CIR-15-0095 [pii] AID - 10.1158/2326-6066.CIR-15-0095 [doi] PST - ppublish SO - Cancer Immunol Res. 2015 Sep;3(9):978-85. doi: 10.1158/2326-6066.CIR-15-0095. Epub 2015 Aug 12.