Tryptophan catabolism and T-cell tolerance: immunosuppression by starvation?
Some macrophages inhibit microbial infections by producing indoleamine 2,3 dioxygenase (IDO), which catabolizes tryptophan. Here, Andrew Mellor and David Munn discuss evidence that cells that synthesize IDO protect the mammalian fetus from maternal T-cell attack and argue that this mechanism might have wider implications for the control of T-cell responses.
Mellor
A L
AL
Molecular Immunology Program, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA 30912, USA. mellor@immag.mcg.edu
Munn
D H
DH
D000818:Animals; D005260:Female; D007108:Immune Tolerance / Q000502:physiology*; D007111:Immunity, Cellular; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D008431:Maternal-Fetal Exchange / Q000276:immunology; D051379:Mice; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D011247:Pregnancy; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism*; D014366:Tryptophan Oxygenase / Q000096:biosynthesis / Q000235:genetics
D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D014364:Tryptophan; D014366:Tryptophan Oxygenase; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse