title: CD4(+)CD25+ T regulatory cells in murine pregnancy.
abstract: 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.
authors.affiliation: 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
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Zenclussen
mesh_terms: 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*
chemical_list: D015375:Receptors, Interleukin-2; D016753:Interleukin-10