title: CD8+ effector T cells at the fetal-maternal interface, balancing fetal tolerance and antiviral immunity.
abstract: During pregnancy CD8+ effector T cells need optimal immune regulation to prevent a detrimental response to allogeneic fetal cells while providing immune protection to infections. A significant proportion of (prospective) mothers carry naïve or memory CD8+ T cells with a TCR that can directly bind to paternal MHC molecules. In addition, a high percentage of pregnant women develop specific T cell responses to fetal minor histocompatibility antigens (mHags). Under normal conditions, fetal-maternal MHC and mHag mismatches lead to elevated lymphocyte activation but do not induce pregnancy failure. Furthermore, viral infections alter the maternal CD8+ T cell response by changing the CD8+ T cell repertoire and increasing the influx of CD8+ T cells to decidual tissue. The normally high T cell activation threshold at the fetal-maternal interface may prevent efficient clearance of viral infections. Conversely, the increased inflammatory response due to viral infections may break fetal-maternal tolerance and lead to pregnancy complications. The aim of this review is to discuss the recent studies of CD8+ T cells in pregnancy, identify potential mechanisms for antigen-specific immune recognition of fetal extravillous trophoblast (EVT) cells by CD8+ T cells, and discuss the impact of viral infections and virus-specific CD8+ T cells during pregnancy.
authors: Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA. tilburgs@FAS.Harvard.edu
authors: Tamara
authors: T
authors: Tilburgs
authors: Jack L
authors: JL
authors: Strominger
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D005333:Fetus / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology; D054502:Histocompatibility, Maternal-Fetal; D006801:Humans; D007108:Immune Tolerance; D007249:Inflammation / Q000276:immunology; D008213:Lymphocyte Activation; D010920:Placenta / Q000276:immunology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D014327:Trophoblasts / Q000276:immunology; D014780:Viruses / Q000276:immunology*
chemical_list: D006680:HLA Antigens; D011948:Receptors, Antigen, T-Cell