Tolerance signaling molecules and pregnancy: IDO, galectins, and the renaissance of regulatory T cells.
OBJECTIVE
Is the concept of maternal tolerance preventing rejection of the semi-allogeneic 'fetal allograft' still valid?


METHODS
Compilation of expert reviews of literature and recent advances in research on indoleamine-2,3 dioxygenase (IDO), regulatory T cells and galectin-1.


CONCLUSIONS
A role for IDO in pregnancy success remains speculative, but solid data exist to support a role for Treg cells, and for galectin-1 in induction and action of Treg cells. Just as several signals may need to be simultaneously present to induce Th1 cytokine-triggered abortions, more than 1 signal may need to be simultaneously present to prevent rejection and ensure success. Both complement and coagulation pathways appear necessary for embryo execution.
Terness
Peter
P
Institute of Immunology, University of Heidelberg, Heidelberg, Germany.
Kallikourdis
Marinos
M
Betz
Alexander G
AG
Rabinovich
Gabriel A
GA
Saito
Shigeru
S
Clark
David A
DA
D004622:Embryo, Mammalian / Q000276:immunology*; D005260:Female; D037483:Galectin 1 / Q000502:physiology*; D006084:Graft Rejection; D006801:Humans; D007108:Immune Tolerance / Q000502:physiology*; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000502:physiology*; D011247:Pregnancy; D015398:Signal Transduction / Q000502:physiology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D037483:Galectin 1; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase