Insights into Therapy: Tryptophan Oxidation and HIV Infection

New data from Favre and colleagues strengthen the link between activation of the tryptophan oxidation (TOx) pathway—via the indoleamine 2,3-dioxygenase enzymes IDO1 and IDO2—and chronic inflammation in progressive HIV disease. It can now be appreciated that a pathogenic TOx activation cycle exists in HIV. TOx regulation is a therapeutic target for other diseases, such as cancer and autoimmune disorders. Here TOx control is examined with an eye to eventual therapeutic intervention in HIV disease.