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Product Usage Information

Storage: Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA and 50% glycerol. Store at –20°C. Do not aliquot the antibody.

Specificity / Sensitivity

IDO Antibody recognizes endogenous levels of total IDO protein.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues near the carboxy terminus of human IDO protein. Antibodies are purified by protein A and peptide affinity chromatography.

INDO/IDO1/indoleamine 2,3-dioxygenase (IDO) is an IFN-γ-inducible enzyme that catalyzes the rate-limiting step of tryptophan degradation (1). IDO is upregulated in many tumors and in dendritic cells in tumor-draining lymph nodes. Elevated tryptophan catabolism in these cells leads to tryptophan starvation of T cells, limiting T cell proliferation and activation (2). Therefore, IDO is considered an immunosuppresive molecule, and research studies have shown that upregulation of IDO is a mechanism of cancer immune evasion (3). The gastrointestinal stromal tumor drug, imatinib, was found to act, in part, by reducing IDO expression, resulting in increased CD8+ T cell activation and induction of apoptosis in regulatory T cells (4). In addition to its enzymatic activity, IDO was recently shown to have signaling capability through an immunoreceptor tyrosine-based inhibitory motif (ITIM) that is phosphorylated by Fyn in response to TGF-β. This leads to recruitment of SHP-1 and activation of the noncanonical NF-κB pathway (5).

1.  Yasui, H. et al. (1986) Proc Natl Acad Sci U S A 83, 6622-6.

2.  Mellor, A.L. et al. (2003) Adv Exp Med Biol 527, 27-35.

3.  Prendergast, G.C. (2008) Oncogene 27, 3889-900.

4.  Balachandran, V.P. et al. (2011) Nat Med 17, 1094-100.

5.  Pallotta, M.T. et al. (2011) Nat Immunol 12, 870-8.

Entrez-Gene Id 3620
Swiss-Prot Acc. P14902

For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.

IDO Antibody