Current Medicinal Chemistry - Volume 18, Issue 15, 2011

Indoleamine 2,3-dioxygenase 1 (IDO1) is a tryptophan-catabolizing enzyme expressed by professional antigen presenting cells such as dendritic cells (DC) or by a variety of cell types at sites of inflammation. IDO1 has been implicated in the development of immune tolerance to tumors. It is likely that IDO1 is not the only immune regulatory molecule but it is part of a more complex network of interactions and regulatory path Read More

The enzyme indoleamine 2,3-dioxygenase (IDO, EC 1.13.11.42) belongs to the family of heme-containing oxidoreductases and catalyzes the first and rate-limiting step in the kynurenine pathway, the major pathway of tryptophan metabolism. IDO is folded into one large and one small distinct α-helical domains, with the heme prosthetic ring positioned between them. The enzyme, through the oxidative properties of the Fe3+ at Read More

Although most CD4+CD25+ regulatory T (Treg) cells develop in the thymus (i.e., natural Treg or nTreg), accumulating evidence suggests that they can also develop in the periphery (adaptive/induced Treg or iTreg). Both types of cells are functionally associated with the expression of Foxp3, a transcription factor that is constitutively expressed in nTreg cells and inducible during iTreg cell generation from CD4+CD25- T lymphocy Read More

In the human immune system, IDO expression and activity (IDO competence), are preferentially found in the antigenpresenting cell population, of which dendritic cells (DCs) represent an essential part. As will be comprehensively reviewed, IDO competence in human DCs, in general, is induced by molecules such as interferon-γ, which otherwise initiate immunity. IDO activity therefore, can be interpreted as a negative feedback Read More

Indoleamine 2,3-dioxygenase (IDO) is an intracellular heme-containing enzyme that catalyzes the initial rate-limiting step in tryptophan degradation along the kynurenine pathway. Recent works have demonstrated a crucial role for IDO in the induction of immune tolerance during infections, pregnancy, transplantation, autoimmunity, and neoplasias. IDO is widely expressed in human tissues and cell subsets, including dendritic Read More

The IDO pathway is implicated in a number of settings which lead to acquired peripheral tolerance. One such setting may be the functional tolerance displayed by tumor-bearing hosts toward tumor-associated antigens. Foxp3+ Tregs are now recognized as a major contributor to tumor-induced immune suppression and functional tolerance. Emerging evidence links the IDO pathway with Treg biology at several points. Th Read More

Indoleamine 2,3-dioxygenase (IDO) is an immunoregulatory enzyme which plays a key role in maintaining the physiologic immune balance between the efficient responses to insulting pathogens and the control of harmful autoimmune reactions. During HIV infection, multiple mechanisms involving both viral and cellular components, contribute to enhance IDO expression and activity in an uncontrolled manner. The downstr Read More

Chronic inflammation underlies the basis for development and progression of cancers and a variety of other disorders, but what specifically defines its pathogenic nature remains largely undefined. Recent genetic and pharmacological studies in the mouse suggest that the immune modulatory enzyme indoleamine 2,3-dioxygenase (IDO), identified as an important mediator of immune escape in cancer, can also contribute to the Read More

The enzyme indoleamine 2,3-dioxygenase 1 (IDO1) degrades the essential amino acid tryptophan into kynurenine and other downstream metabolites that suppress effector T-cell function and favor the differentiation of regulatory T cells. IDO1 is traditionally viewed as a general suppressor of T-cell activation and mediator of immune escape in cancer. Recently, evidence has emerged to support a greater function Read More

Pathologic heart conditions, particularly heart failure (HF) and ischemia-reperfusion (I/R) injury, are characterized by sustained elevation of plasma and interstitial catecholamine levels, as well as by the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Despite the continuous and extensive research on catecholamines since the early years of the XXth century, the mechanisms underlying catechola Read More

Plant foods are not only a main source of nutrients, but they are also rich in physiologically bioactive bionutrients or phytochemicals. Consumption of fruit and vegetables is associated with a decreased risk of pathological status, including cancer. Reactive oxygen species play a key role in the genesis and development of cancer. Therefore, antioxidant functions of phytonutrients have been thoroughly investigated in the last yea Read More

Sickle Cell Disease (SCD) is one of the most prevalent hematological diseases in the world. SCD is a genetic disease characterized by punctual mutation that basis on the exchange of glutamic acid to valine in a beta chain of hemoglobin. In deoxygenated state, the interaction among the beta chains leads to hemoglobin polymerization carrying out to deformation of cytoskeleton structure of red blood cells to a sickle shape Read More