Authors:
Munn DH, Zhou M, Attwood JT, Bondarev I, Conway SJ, Marshall B, Brown C, & Mellor AL
Summary:
In 1953 Medawar pointed out that survival of the genetically disparate (allogeneic) mammalian conceptus contradicts the laws of tissue transplantation. Rapid T cell-induced rejection of all allogeneic concepti occurred when pregnant mice were treated with a pharmacologic inhibitor of indoleamine 2,3-dioxygenase (IDO), a tryptophan-catabolizing enzyme expressed by trophoblasts and macrophages. Thus, by catabolizing tryptophan, the mammalian conceptus suppresses T cell activity and defends itself against rejection.
Source:
Science; 1998 Aug 21; 281(5380):1191-3