CD4(+)CD25+ T regulatory cells in murine pregnancy.
Mammalian pregnancy is thought to be a state of immunological tolerance and immunological pregnancy complications may result from incomplete allo-tolerance. We reported recently a higher frequency of Th1 cytokine-producing T cells specific against paternal antigens in abortion-prone mice compared to normal pregnant mice. Since Th2 cells were shown to be not essential for normal pregnancy; alloreactive Th1 cells must be differently regulated. In this context, T regulatory cells (Treg) were proposed to play an essential role. Normal pregnant mice show an expansion of CD4(+)CD25+ and IL-10+ Treg cells at the periphery compared to non-pregnant animals. Further, we reported significantly lower frequencies of Treg in abortion-prone mice. Interestingly, CD4(+)CD25+ Treg cells from normal pregnant mice were able to prevent fetal rejection. Accordingly, down-regulated levels of Treg were also reported during human miscarriage. The putative mechanisms involved in Treg-induced tolerance in mice and humans are discussed in this review.
Zenclussen
Ana Claudia
AC
Institute of Medical Immunology, Medical University Berlin, Biomedizinisches Forschungszentrum, Raum 2.0534, Charité, Campus Virchow Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany. ana.zanclussen@charite.de
D000818:Animals; D005260:Female; D016753:Interleukin-10 / Q000276:immunology*; D051379:Mice; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D015375:Receptors, Interleukin-2; D016753:Interleukin-10