Related Experiment Video
Updated: Jun 30, 2026

Trans-vivo Delayed Type Hypersensitivity Assay for Antigen Specific Regulation
Published on: May 2, 2013
IDO: a double-edged sword for T(H)1/T(H)2 regulation
Hui Xu1, Guang-Xian Zhang, Bogoljub Ciric
1Department of Neurology, Thomas Jefferson University, 900 Walnut Street, Philadelphia, PA 19107, USA. hui.xu@jefferson.edu
Abstract:
Indoleamine 2,3-dioxygenase (IDO) has been well defined as one of the important immunosuppressive properties for T(H)1 cell-mediated immune responses, but its function in T(H)2 dominant system is poorly understood. Recently, an appreciable number of publications suggest that the role of IDO in T(H)2 cell regulation may be different from that of T(H)1 immune responses. Here we review the evidence on the regulatory function of IDO and tryptophan metabolites in T(H)1/T(H)2 differentiation. We propose that IDO-kynurenine pathway can serve as a negative feedback loop for T(H)1 cells but it may play a distinct role in up-regulating T(H)2 dominant immune responses.
Related Concept Videos
T Cell Types and Functions
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
Regulation of Hematopoietic Stem Cells
Inflammatory Response
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...
B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...

