title: Expression of killer immunoglobulin-like receptors on peripheral blood NK cell subsets of women with recurrent spontaneous abortions or implantation failures.
abstract: OBJECTIVE
  Decidual natural killer (NK) cells express inhibitory receptors (killer immunoglobulin-like receptors, KIRs), which bind to ligands on trophoblast cells (human leucocyte antigen, HLA-C). This interaction appears to block NK cytotoxicity against trophoblast cells. In this study, we investigated the expression of inhibitory and activating receptors in peripheral blood NK cells of women with recurrent spontaneous abortion (RSA) or implantation failures.
  
  
  METHODS
  CD56(dim)/CD16(+), CD56(bright)/CD16(-) NK cells and CD56(+)/CD3(+) NKT cells of women with RSA or in vitro fertilization (IVF) failures and normal controls were analyzed for the expression of CD158a, CD158b inhibitory KIRs or CD161-activating receptors, by flow cytometric analysis.
  
  
  RESULTS
  CD158a and CD158b inhibitory receptor expression by CD56(dim)/CD16(+) and CD56(bright)/CD16(-) NK cells were significantly decreased, and CD161-activating receptor expression by CD56(+)/CD3(+) NKT cells was significantly increased in women with implantation failures when compared with normal controls.
  
  
  CONCLUSIONS
  An imbalance between inhibitory and activating receptor expression was found in NK cells of women with implantation failures. This imbalance may explain the adverse reproductive outcome.
authors.affiliation: Department of Clinical Immunology, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA.
authors.forename: Evangelos I
authors.initials: EI
authors.lastname: Ntrivalas
authors.forename: Chad R
authors.initials: CR
authors.lastname: Bowser
authors.forename: Joanne
authors.initials: J
authors.lastname: Kwak-Kim
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Beaman
authors.forename: Alice
authors.initials: A
authors.lastname: Gilman-Sachs
mesh_terms: D000026:Abortion, Habitual / Q000276:immunology*; D000328:Adult; D000954:Antigens, Surface / Q000276:immunology; D010064:Embryo Implantation / Q000276:immunology; D005260:Female; D005307:Fertilization in Vitro; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type / Q000276:immunology; D016131:Lymphocyte Subsets / Q000276:immunology*; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011971:Receptors, Immunologic / Q000276:immunology*; D054340:Receptors, KIR; D054342:Receptors, KIR2DL1; D054344:Receptors, KIR2DL3
chemical_list: D000954:Antigens, Surface; C527203:KLRB1 protein, human; D037181:Lectins, C-Type; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054342:Receptors, KIR2DL1; D054344:Receptors, KIR2DL3