title: KIR2DL1-HLA signaling pathway: notable inhibition in the cytotoxicity of allo-NK cell against KG1A cell.
abstract: BACKGROUND
  KIR2DL1 is an important member of killer cell immunoglobulin-like receptors (KIRs). It recognizes the C2 group of alleles exclusively and delivers signals that inhibit NK cell cytotoxicity.
  
  
  METHODS
  In this study, NK cells were isolated by magnetic activated cell sorting (MACS) from peripheral blood of 12 healthy unrelated male donors. Flow cytometry (FCM) was used to evaluate the purity of NK cells and phenotypic KIR2DL1 expression on them. The lysis of KG1A and K562 cells by NK cells was analyzed in the lactate dehydrogenase (LDH) assay to investigate whether KIR2DL1 expression on NK cells would affect the cytotoxicity.
  
  
  RESULTS
  Significant differences in KIR2DL1 frequency were noted among the donors (range, 27.14% - 92.49%). NK cells with lower KIR2DL1 expression exerted higher cytolytic activity against KG1A cells, whereas those with higher KIR2DL1 expression exerted significantly lower lysis against KG1A cells (R2 = 0.8169, p < 0.05).
  
  
  CONCLUSIONS
  KIR2DL1 expression frequency was negatively correlated with the cytotoxicity of NK cells against KG1A cells. This study discovered that differential KIR2DL1 expression could positively affect the lytic activity of NK cells against KG1A cells, suggesting potential clinical value of KIR2DL1 selection in the treatment of acute myeloid leukemia (AML) patients.
authors.affiliation: Department of Hematology, Zhujiang Hospital, Southern Medical University, 510282 Guangzhou, China.
authors.forename: Tong-Yuan
authors.initials: TY
authors.lastname: Xue
authors.forename: Ying-Zhi
authors.initials: YZ
authors.lastname: He
authors.forename: Jia-Jia
authors.initials: JJ
authors.lastname: Zhang
authors.forename: Xuan-Yu
authors.initials: XY
authors.lastname: Zhang
authors.forename: Yong-Jie
authors.initials: YJ
authors.lastname: Xin
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Li
mesh_terms: D019002:CD56 Antigen; D016923:Cell Death / Q000502:physiology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D005434:Flow Cytometry; D015236:HLA-C Antigens / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000166:cytology / Q000378:metabolism*; D008297:Male; D054342:Receptors, KIR2DL1 / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D019002:CD56 Antigen; D015236:HLA-C Antigens; C093100:KIR2DL1 protein, human; C522918:NCAM1 protein, human; D054342:Receptors, KIR2DL1