title: Differential expression of natural killer activating and inhibitory receptors in patients with newly diagnosed systemic lupus erythematosus.
abstract: OBJECTIVE
  Systemic lupus erythematosus (SLE) presents as the abnormal activation and over-proliferation of immune competent cells. Few studies have characterized the role of natural killer (NK) and NK T (NKT) cells in the pathogenesis of SLE, and therefore a consensus has not been reached as yet.
  
  
  METHODS
  Thirty-two patients with new-onset SLE and 15 healthy controls were recruited. Activated and inhibitory NK and NKT cells in peripheral blood were quantified by flow cytometry. The proportions of spontaneous and stimulated interferon (IFN)-γ(+) NK and NKT cells and CD107a(+) NK cells was examined. Finally, the potential relationship between the cell subsets and clinical indexes was analyzed.
  
  
  RESULTS
  The proportions of NK and NKT cells (P = 0.002 and 0.004, respectively) as well as the proportions of NKG2C(+) NK cells, inhibitory NK and NKT cell subsets (P = 0.016, P = 0.019, P = 0.049, and P = 0.028, respectively) in SLE patients were significantly lower than those in controls. In contrast, the proportions of activated NK cells and NKT cell subsets were significantly higher (P = 0.036, P = 0.034, P = 0.005, and P = 0.007, respectively). Moreover, the proportions of stimulated IFN-γ(+) NKT cells were significantly higher than in the controls, and the proportions of stimulated CD107a(+) NKT cells in SLE patients were significantly lower than in the controls (P = 0.032 and P = 0.02, respectively).
  
  
  CONCLUSIONS
  Lower proportions of NK and NKT cells, higher proportions of activated NK cells and activated NKT cells, lower proportions of inhibitory NK and NKT cells, higher NKT cell activity, and lower NKT cell degranulation may induce the autoimmune reaction involved in the pathogenesis of SLE.
authors.affiliation: Department of Rheumatology, The First Hospital, Jilin University, Changchun, China.
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Ye
authors.affiliation: Department of Rheumatology, The First Hospital, Jilin University, Changchun, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Ma
authors.affiliation: Department of Rheumatology, The First Hospital, Jilin University, Changchun, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Rheumatology, The First Hospital, Jilin University, Changchun, China.
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Jiang
authors.affiliation: Department of Key Laboratory for Zoonosis Research, Ministry of Education, The First Hospital, Jilin University, Changchun, China.
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Jiang
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015550:Cell Degranulation; D002478:Cells, Cultured; D002648:Child; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D008213:Lymphocyte Activation; D052118:Lysosomal-Associated Membrane Protein 1 / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D055654:NK Cell Lectin-Like Receptor Subfamily C / Q000097:blood / Q000276:immunology; D055611:Natural Killer T-Cells / Q000276:immunology / Q000378:metabolism*; D010641:Phenotype; D055607:Receptors, Natural Killer Cell / Q000097:blood* / Q000276:immunology; D055815:Young Adult
chemical_list: D015415:Biomarkers; C573415:IFNG protein, human; C527059:KLRC2 protein, human; D052118:Lysosomal-Associated Membrane Protein 1; D055654:NK Cell Lectin-Like Receptor Subfamily C; D055607:Receptors, Natural Killer Cell; D007371:Interferon-gamma
keywords: CD107a; IFN-γ; NK cells; NKT cells; SLE