title: [Effects of blocking inhibitory KIR receptors on cytotoxic activity of human NK cells in vitro].
abstract: To investigate the effect of blocking the inhibitory receptors KIR2DL1 and KIR2DL2/2DL3 with monoclonal antibody on cytotoxic activity of human NK cells.
  
  
  
  Human peripheral blood NK cells were isolated by Rosettesep NK sorting kit. The cytotoxic activity of NK cells against human leukemia NB4, K-562, Raji cells and allogeneic mature or dendritic cells (DCs) was detected before or after KIR2DL1 and KIR2DL2/2DL3 were blocked. The effect of NK cells on T lymphocyte proliferation was detected by mixed lymphocyte reaction and TGF-β1 concentration in culture supernatant was measured.
  
  
  
  The cytotoxicity of NK cells to NB4 cells was augmented with increasing concentration of the antibody. Combination of both antibodies enhanced killing activity of NK cells. NK cells had strong cytotoxicity to K-562 cells, but were not enhanced by the blockade of inhibitory receptors. The cytotoxicity to Raji cells was not evidently augmented. The cytotoxicity of NK cells to mature DC was enhanced remarkably with the increase of concentration of the antibodies (2.20% ±1.10% compared with 37.59% ±5.06%, P<0.05). In mixed lymphocyte reaction, the blockade of two antibodies enhanced the inhibition effect of NK cells on T cell proliferation (77.85% ± 8.31% compared with 43.05% ± 5.95%, P<0.05) and the content of TGF-β1 in the supernatant was increased.
  
  
  
  The cytotoxic effects of human NK cells against target cells were significantly enhanced with the blockade of inhibitory KIR receptor; and the cytokine TGF-β1 secreted by NK cells further inhibits T cells proliferation.
authors: Institute of Hematology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
authors: Gong-qiang
authors: GQ
authors: Wu
authors: Yan-min
authors: YM
authors: Zhao
authors: He
authors: H
authors: Huang
authors: Xiao-yu
authors: XY
authors: Lai
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology*; D002460:Cell Line; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D007959:Lymphocyte Culture Test, Mixed; D054342:Receptors, KIR2DL1 / Q000187:drug effects* / Q000276:immunology; D054343:Receptors, KIR2DL2 / Q000187:drug effects* / Q000276:immunology; D054344:Receptors, KIR2DL3 / Q000187:drug effects* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; C093100:KIR2DL1 protein, human; C515077:KIR2DL2 protein, human; C515078:KIR2DL3 protein, human; D054342:Receptors, KIR2DL1; D054343:Receptors, KIR2DL2; D054344:Receptors, KIR2DL3; D053773:Transforming Growth Factor beta1