title: Cytotoxic potential of IL-15-activated cytokine-induced killer cells against human neuroblastoma cells.
abstract: Neuroblastoma (NB) is the most common solid extracranial tumor in childhood. Despite advances in therapy, the prognosis is poor and optimized therapies are urgently needed. Therefore, we investigated the antitumor potential of interleukin-15 (IL-15)-activated cytokine-induced killer (CIK) cells against different NB cell lines.
  
  
  
  CIK cells were generated from peripheral blood mononuclear cells by the stimulation with interferon-γ (IFN-γ), IL-2, OKT-3 and IL-15 over a period of 10-12 days. The cytotoxic activity against NB cells was analyzed by nonradioactive Europium release assay before and after blocking of different receptor-ligand interactions relevant in CIK cell-mediated cytotoxicity.
  
  
  
  The final CIK cell products consisted in median of 83% (range: 75.9-91.9%) CD3+CD56-T cells, 14% (range: 5.2-20.7%) CD3+CD56+NK-like T cells and 2% (range: 0.9-4.8%) CD3-CD56+NK cells. CIK cells expanded significantly upon ex vivo stimulation with median rates of 22.3-fold for T cells, 58.3-fold for NK-like T cells and 2.5-fold for NK cells. Interestingly, CD25 surface expression increased from less than equal to 1% up to median 79.7%. Cytotoxic activity of CIK cells against NB cells was in median 34.7, 25.9 and 34.8% against the cell lines UKF-NB-3, UKF-NB-4 and SK-N-SH, respectively. In comparison with IL-2-stimulated NK cells, CIK cells showed a significantly higher cytotoxicity. Antibody-mediated blocking of the receptors NKG2D, TRAIL, FasL, DNAM-1, NKp30 and lymphocyte function-associated antigen-1 (LFA-1) significantly reduced lytic activity, indicating that diverse cytotoxic mechanisms might be involved in CIK cell-mediated NB killing.
  
  
  
  Unlike the mechanism reported in other malignancies, NKG2D-mediated cytotoxicity does not constitute the major killing mechanism of CIK cells against NB.
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cappel
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany. sabine.huenecke@kgu.de.
authors.forename: Sabine
authors.initials: S
authors.lastname: Huenecke
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Anica
authors.initials: A
authors.lastname: Suemmerer
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Erben
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Rettinger
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Pfirrmann
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Annekathrin
authors.initials: A
authors.lastname: Heinze
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Olga
authors.initials: O
authors.lastname: Zimmermann
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Klingebiel
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Ullrich
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bader
authors.affiliation: Department for Stem Cell Transplantation and Immunology, Clinic for Children and Adolescents, University Hospital Frankfurt, Goethe University, Frankfurt/Main, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Bremm
mesh_terms: D045744:Cell Line, Tumor; D055612:Cytokine-Induced Killer Cells / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D006801:Humans; D019409:Interleukin-15 / Q000494:pharmacology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000502:physiology; D009447:Neuroblastoma / Q000473:pathology / Q000628:therapy*
chemical_list: D019409:Interleukin-15; C527085:KLRK1 protein, human; D016169:Lymphocyte Function-Associated Antigen-1; D055655:NK Cell Lectin-Like Receptor Subfamily K
keywords: CIK (cytokine-induced killer) cells; immunotherapy; neuroblastoma