Abstract
Indoleamine - 2,3 - dioxygenase (IDO) is an enzyme that catabolizes tryptophan, an essential amino acid necessary for T cells proliferation, therefore compromising its activity (BARKSDALE et al., 2004). IDO is expressed by several types of cells, including monocytes-derived macrophages and dendritic cells (MUNN et al., 2004). Evaluating the presence of IDO in blood cells and organs of rai…