Indoleamine 2,3-dioxygenase (IDO), an enzyme involved in the catabolism of tryptophan, is expressed by a variety of cells and tissues such as macrophages, dendritic cells, cells of the endocrine system and by the placenta. IFN- γ is the main inducer of this enzyme. IDO acts as an important defense mechanism of innate immunity against pathogens. It also has tumor suppressive activity and prolong...

indoleamine 2,3-dioxygenase (ido), an enzyme involved in the catabolism of tryptophan, is expressed by a variety of cells and tissues such as macrophages, dendritic cells, cells of the endocrine system and by the placenta. ifn- γ is the main inducer of this enzyme. ido acts as an important defense mechanism of innate immunity against pathogens. it also has tumor suppressive activity and prolong...

a wide range of biological activities of garlic in vitro and in vivo have been verified including its antioxidant, antitumor and anti-inflammatory effects. indoleamine 2,3-dioxygenase (ido) is an enzyme widely distributed in mammals and is inducible preferentially by ifn-γ. ido degrades the essential amino acid tryptophan to form n-formyl kynurenine. in the present in vitro study, the modulator...

The activity of IDO that catalyzes the degradation of tryptophan (Trp) into kynurenine (Kyn) increases after diseases caused by different infectious agents. Previously, we demonstrated that IDO has an important immunomodulatory function in immune-related diseases. However, the pathophysiological role of IDO following acute viral infection is not fully understood. To investigate the role of IDO ...

To study the role of indoleamine 2,3-dioxygenase (IDO) in immune response and immune escape in gastric cancer, the human IDO gene was cloned by reverse transcription-polymerase chain reaction (RT-PCR) and inserted into the pIRES2-EGFP vector to construct the IDO expression vector (pIRES2-EGFP-IDO). BGC-823 cells were transfected with the vector by electroporation and selected stable expression ...

In patients with hepatitis C virus (HCV) infection, enhanced activity of indoleamine-2,3-dioxygenase 1 (IDO) has been reported. IDO - a tryptophan-catabolizing enzyme - has been considered as both an innate defence mechanism and an important regulator of the immune response. The molecular mechanism of IDO induction in HCV infection and its role in the antiviral immune response remain unknown. U...

Dendritic cells (DCs) can induce tolerance or immunity. We identified and characterized an IDO-expressing and an IDO-negative human DC population after stimulation by various proinflammatory stimuli. IDO expression was strongly dependent on the maturation status of the cells (CD83-positive cells only). The two DC subpopulations remained IDO positive and IDO negative, respectively, over a time p...

BACKGROUND The enzyme indoleamine 2,3-dioxygenase (IDO) contributes to immune tolerance in a variety of settings. In cancer IDO is expressed within the tumor itself as well as in antigen-presenting cells in tumor-draining lymph nodes, where it endorses the establishment of peripheral immune tolerance to tumor antigens. Recently, we described cytotoxic CD8(+) T-cell reactivity towards IDO-derive...

Indoleamine-2,3-dioxygenase (IDO) inhibitors have entered clinical trials based on their ability to restore anti-tumor immunity in preclinical studies. However, the mechanisms leading to constitutive expression of IDO in human tumors are largely unknown. Here we analyzed the pathways mediating constitutive IDO expression in human cancer. IDO-positive tumor cells and tissues showed basal phospho...