T lymphocytes to IDO+ cells: check.

摘要

Sorensen and colleagues have described a population of IDO-specific CD8+ T cells that may function as regulators of immune responses. IDO has long been examined as an enzyme critical in immune suppression: it cleaves the pyrrole ring of L-tryptophan, an essential amino acid consumed (not synthesized) by humans. IDO exerts its suppressive effects via reduction of the local tryptophan concentration and the creation of tryptophan metabolites capable of immune modulation. Cell types known to express this molecule in humans include certain dendritic cell (DC) subsets, macrophages, endothelial cells, fibro-blasts, and tumor cells.