Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2020 Mar 24;10:276. doi: 10.3389/fonc.2020.00276

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2020 Fahrmann, Vykoukal and Ostrin.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

PMC Copyright notice

The tryptophan catabolic pathway. Changes in this pathway, including tryptophan depletion and accumulation of catabolites kynurenine, 3-hydroxyanthranilate, and anthranilic acid have immunomodulatory effects, with specific effects on CD8 T cells and regulatory T (Treg) cells. IDO1 and IDO2, indoleamine 2,3-dioxygenase 1 and 2; TDO, tryptophan 2,3-dioxygenase; KYNU, kynureninase; AH, anthranilate hydrolase; HAAO, 3-hydroxyanthranilate 3,4-dioxygenase; QPRT, quinolinate phosphoribosyl transferase.