The Janus-faced nature of IDO1 in infectious diseases: challenges and therapeutic opportunities

Inhibition of IDO1 is a strategy pursued to develop novel therapeutic treatments for cancer. Recent years have witnessed growing evidence that the enzyme plays a pivotal role in viral, bacterial and fungal infections. These studies have underscored the Janus-faced nature of IDO1 in the regulation of host-pathogen interactions and commensalism. Starting with an outlook on the advances in the structural features of IDO1, herein we report recent findings that pinpoint the involvement of IDO1 in infectious diseases. Then, we present an overview of IDO1 inhibitors that have been enrolled in clinical trials as well as other distinct modulators of the enzyme