Ido

IDO is the acronym for "indoleamine-2,3-dioxygenase", an enzyme that degrades tryptophane to N-formylkynurenine.

IDO belongs to the family of anti-inflammatory immune checkpoints (ICs). Anti-inflammatory immune checkpoints inhibit the immune reactivity of T lymphocytes, in contrast to pro-inflammatory ICs, which increase the immune reactivity of T lymphocytes. The immune checkpoints are activated by precisely fitting cytokines (ligands) that are presented and released by other cells.

Indoleamine-2,3-dioxygenase is produced in all tissues of the human body, but especially in the tonsils and placenta, where the degradation of tryptophane has a purpose beyond normal catabolism: to support the immune system in the event of infection on the one hand, and to prevent fetal rejection on the other. Due to its immunosuppressive effect, this enzyme is a suitable target protein for achieving longer acceptance of transplants. Furthermore, its inhibition could have an oncosuppressive effect.