title: Effect of Indoleamine 2,3-Dioxygenase Expressed in HTR-8/SVneo Cells on Decidual NK Cell Cytotoxicity.
abstract: OBJECTIVE
  To study the effect of indoleamine 2,3-dioxygenase (IDO) expressed in HTR-8/SVneo cells on NKG2D and NKp46 expression and cytotoxicity of decidual NK (dNK) and peripheral NK (pNK) cells.
  
  
  METHODS
  CD56(+) dNK and pNK cells purified were cultured with HTR-8/SVneo cell conditioned medium (CM), 1-MT+HTR-8/SVneo cell CM, and complete RPMI 1640 medium (negative control) in vitro. The mRNA and protein expression of NKG2D and NKp46 in NK cells were then assessed by qRT-PCR and flow cytometry, respectively. Their cytotoxicity was evaluated with LDH assays, and TNF-α secretion was analyzed by ELISA.
  
  
  RESULTS
  For dNK cells, the mRNA and protein expression of NKp46 as well as NKG2D did not differ significantly among the three groups (P > 0.05), whereas for pNK cells, the expression level was significantly decreased in HTR-8/SVneo cell CM group than the other two groups (P < 0.01). Peripheral NK cells cultured with HTR-8/SVneo cell CM showed reduced cytotoxicity and TNF-α secretion than the other two groups (P < 0.01), although there were no significant differences among three groups for dNK cells (P > 0.05).
  
  
  CONCLUSIONS
  IDO expressed by HTR-8/SVneo cells can down-regulate NKp46 and NKG2D expression and reduce cytotoxicity in pNK cells, and may contribute to keep dNK cytotoxicity at a low level, suggesting an important role for IDO in the maintenance of normal pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Ji'nan, Shandong, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Ban
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Ji'nan, Shandong, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Ji'nan, Shandong, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Ji'nan, Shandong, China.
authors.forename: Baihua
authors.initials: B
authors.lastname: Dong
authors.affiliation: Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Ji'nan, Shandong, China.
authors.forename: Beihua
authors.initials: B
authors.lastname: Kong
authors.affiliation: Institute of Basic Medical Sciences, Qilu Hospital of Shandong University, Ji'nan, Shandong, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Qu
mesh_terms: D001773:Blood Cells / Q000502:physiology*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D003656:Decidua / Q000473:pathology*; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics; D006801:Humans; D007108:Immune Tolerance; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000235:genetics / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000502:physiology*; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000235:genetics / Q000378:metabolism; D055627:Natural Cytotoxicity Triggering Receptor 1 / Q000235:genetics / Q000378:metabolism; D011247:Pregnancy / Q000276:immunology*; D019076:Transgenes / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; C527085:KLRK1 protein, human; C112260:NCR1 protein, human; D055655:NK Cell Lectin-Like Receptor Subfamily K; D055627:Natural Cytotoxicity Triggering Receptor 1; D014409:Tumor Necrosis Factor-alpha
keywords: 3-Dioxygenase; NK cells; decidua; indoleamine 2; pregnancy; trophoblast