Letter to the Editor
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 7, 2023; 29(17): 2701-2703
Published online May 7, 2023. doi: 10.3748/wjg.v29.i17.2701
T cells in pancreatic cancer stroma: Tryptophan metabolism plays an important role in immunoregulation
Ting Yang, Qiao-Qi Li, Yong-Mei Liu, Biao Yang
Ting Yang, Qiao-Qi Li, Biao Yang, Department of Abdominal Oncology, Division of Medical Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Yong-Mei Liu, Division of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Yang T, Li QQ, Liu YM, and Yang B designed the research study; Yang T and Li QQ performed the research; Yang T, Li QQ, and Yang B analyzed the data and wrote the manuscript; All authors read and approved the final manuscript.
Supported by National Natural Science Foundation of China, No. 82200695.
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Biao Yang, MD, PhD, Professor, Surgeon, Teacher, Department of Abdominal Oncology, Division of Medical Oncology, Cancer Center, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu 610041, Sichuan Province, China. landayb@163.com
Received: December 7, 2022
Peer-review started: December 7, 2022
First decision: January 22, 2023
Revised: February 10, 2023
Accepted: April 4, 2023
Article in press: April 4, 2023
Published online: May 7, 2023
Processing time: 150 Days and 23.9 Hours
Core Tip

Core Tip: There are numerous lines for evidence for tryptophan metabolism, which serves as an immunomodulatory factor. Indoleamine2,3-dioxygenase1 (IDO1) overexpression inhibits the maturation of dendritic cells and T-cell proliferation in the spleen. The high expression of kynurenine induces and activates the aryl hydrocarbon receptor, resulting in upregulated programmed cell death protein 1 expression. The induction of IDO1 can lead to loss of T helper 17 cell/regulatory T cell balance. We also found that overexpression of IDO1 upregulated CD8+ T cells and reduced natural killer T cells in PC in mice.