title: A Phenotypic Analysis of Regulatory T Cells and Uterine NK Cells from First Trimester Pregnancies and Associations with HLA-G.
abstract: OBJECTIVE
  The prevalence of regulatory T cells and NK cells expressing activation and HLA-G receptors, and the influence of in vivo sHLA-G and mHLAG on HLA-G receptors expressed by NK cells in the uterine compartment is unclear.
  
  
  METHODS
  KIR2DL4 and/or ILT2 expression on regulatory T cells and NK cells from the placental bed and peripheral blood in first trimester was assessed using flow cytometry. Expression of mHLA-G on trophoblast cells and sHLA-G in 'uterine' and peripheral blood was determined with ELISA and flow cytometry, and specific associations with expression levels of cognate receptors or activation markers on immune cells were determined.
  
  
  RESULTS
  In the placental bed, CD45RA surface expression on Tregs was similar to peripheral Tregs in pregnant women, but T cells with lower CD4 and CD8 expression were accumulated. HLA-G receptor expression was increased on NK cells from 'uterine blood'. Soluble HLA-G was significantly increased in 'uterine blood' compared with peripheral blood, but no correlation was found between sHLA-G and mHLA-G in the uterine compartment. A correlation was found between sHLA-G and the fraction of KIR2DL4-positive NK cells in the uterine compartment, and a tendency was observed between mHLA-G and the fraction of ILT2-positive NK cells in the uterine compartment.
  
  
  CONCLUSIONS
  The NK subset in the placental bed displays a unique phenotype that may be influenced by mHLA-G on trophoblast cells and locally accumulated sHLA-G in the uterus.
authors: Department of Clinical Biochemistry, Centre for Immune Regulation and Reproductive Immunology (CIRRI), Copenhagen University Hospital (Roskilde), University of Copenhagen, Roskilde, Denmark.
authors: Snezana
authors: S
authors: Djurisic
authors: Department of Obstetrics and Gynaecology, Copenhagen University Hospital (Roskilde), Roskilde, Denmark.
authors: Lillian
authors: L
authors: Skibsted
authors: Department of Clinical Biochemistry, Centre for Immune Regulation and Reproductive Immunology (CIRRI), Copenhagen University Hospital (Roskilde), University of Copenhagen, Roskilde, Denmark.
authors: Thomas Vauvert F
authors: TV
authors: Hviid
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000378:metabolism*; D005260:Female; D059951:HLA-G Antigens / Q000378:metabolism*; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000378:metabolism*; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*; D054345:Receptors, KIR2DL4 / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000378:metabolism*; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D059951:HLA-G Antigens; C515079:KIR2DL4 protein, human; C105299:LILRB1 protein, human; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D011971:Receptors, Immunologic; D054345:Receptors, KIR2DL4
keywords: HLA-G; Tregs; immune modulation; pregnancy; uNK cells