Indoleamine 2,3-dioxygenase

Indoleamine 2,3-dioxygenase (IDO or INDO EC 1.13.11.52) is an enzyme that catalyzes the oxidative cleavage of tryptophan to kynurenine. This enzyme is widely distributed in humans and other mammals and is involved in the immune response and the biosynthesis of nicotinamide adenine dinucleotide (NAD+).

Function

IDO is an immune checkpoint molecule in the sense that it is induced in various cell types at the tumor site by inflammatory stimuli, especially interferon gamma (IFNγ). The expression of IDO by tumors and antigen-presenting cells in the tumor microenvironment is known to cause local tryptophan depletion and high local kynurenine concentrations. This has multiple effects on the cells in the tumor environment.

Clinical significance

IDO is thought to play a role in various disease states such as cancer, chronic infections, and autoimmune diseases. IDO is also thought to be involved in the pathology of diseases of the nervous system, including Alzheimer's disease, Huntington's disease, and multiple sclerosis.

See also

• Tryptophan
• Kynurenine
• Interferon gamma
• Immune checkpoint
• Alzheimer's disease
• Huntington's disease
• Multiple sclerosis

External links

• Indoleamine 2,3-dioxygenase at the US National Library of Medicine Medical Subject Headings (MeSH)

Indoleamine 2,3-dioxygenase Resources
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