Avoidance of immunosurveillance is presently considered as a hallmark of cancer. Indoleamine 2,3-dioxygenase (IDO) is a cytosolic enzyme which metabolizes L-tryptophan to kynurenines and induces T cell suppression either directly on T cells, or by altering antigen presenting cell function and generating regulatory T cells (Treg). Recently, IDO expression by cancer cells and/or cancer-associated stromal cells has been correlated with the induction of immune dysfunction by human solid tumors, such as ovarian and colon cancer. It has been previously shown that IDO may be expressed by human acute myeloid leukemia, where it promotes the differentiation of Treg cells (
Disclosures: No relevant conflicts of interest to declare.