Work

Regulatory T cells induce a privileged tolerant microenvironment at the fetal‐maternal interface

Year: 2005

Type: article

Abstract: The mechanisms underlying immune tolerance during pregnancy are poorly understood. In this regard, Treg seem to play an important role in mediating maternal tolerance to the fetus. We proposed a crucial role of T regulatory cells (Treg) in avoiding immunological rejection of the fetus after observing diminished number and function of Treg in abortion-prone mice. We further confirmed the protective role of Treg during pregnancy by transferring pregnancy-induced Treg into abortion-prone mice, which prevented rejection. Here, we analyzed the mechanisms involved in Treg-mediated protection. As expected, Treg therapy prevented abortion, while expanding the peripheral and thymic Treg population. Surprisingly, the decidual levels of the Th1 cytokines IFN-gamma and TNF-alpha were not diminished after therapy. Interestingly, the mRNA levels of leukemia inhibitory factor, TGF-beta and heme oxygenase-1 at the fetal-maternal interface were dramatically up-regulated after Treg transfer, while the levels of indolamine 2,3-dioxygenase remained unchanged. Our data suggest that Treg treatment can not prevent T cell infiltration or high Th1 levels but is able to create a privileged tolerant microenvironment at the fetal-maternal interface, further shedding light onto the molecular mechanisms involved in pregnancy tolerance.

Source: European Journal of Immunology

DOI: 10.1002/eji.200535428