背景介绍 L-tryptophan (L-Trp) is an essential amino acid necessary for protein synthesis in mammalian cells and the L-Trp to kynurenine (Kyn) pathway is firmly established as a key regulator of innate and adaptive immunity. Catabolism of L-Trp to Kyn maintains an immunosuppressive microenvironment by starving immune cells of L-Trp and releasing degradation products of L-Trp that have immunosuppressive functions. Tryptophan 2,3 dioxygenase (TDO), one of the rate limiting enzymes in this pathway, is upregulated in many tumors, providing cancer cells with an avenue for immune evasion. 产品介绍 The human TDO Cell-Based Assay Kit is designed to monitor the activity of exogenously expressed human TDO in cultured cells.