title: The cytotoxic action of the CD56+ fraction of cytokine-induced killer cells against a K562 cell line is mainly restricted to the natural killer cell subset.
abstract: BACKGROUND
  Cytokine-induced killer cells are polyclonal T cells generated ex vivo and comprise two main subsets: the CD56- fraction, possessing an alloreactive potential caused by T cells (CD3+CD56-), and the CD56+ fraction, characterised by a strong antitumour capacity induced by natural killer-like T cells (NK-like T, CD3+CD56+) and natural killer cells (NK, CD3-CD56+ bright).
  
  
  METHODS
  We investigated the cytotoxic action of selected CD56+ cell subpopulations against a human chronic myeloid leukaemia (K562) cell line.
  
  
  RESULTS
  After immunomagnetic selection of the CD56+ cell fraction, NK bright cells (CD3-CD56+ bright) and two subsets of NK-like T cells (CD3+CD56+), called NK-like T CD56 dim and NK-like T CD56 bright, could be identified. The cytotoxic effect against K562 cells was mainly exerted by the NK bright subpopulation and resulted to be inversely correlated with the percentage of NK-like T CD56 dim cells in the culture. The lytic action appeared to be independent of cell degranulation as suggested by the lack of change in the expression of CD107a.
  
  
  CONCLUSIONS
  We conclude that the cytotoxic action of CD56+ cells against a K562 cell line is mainly due to the NK cells.
authors.affiliation: Advanced Cellular Therapy Laboratory, Department of Cellular Therapy and Haematology, San Bortolo Hospital, Vicenza, Italy.|Haematology Project Foundation, Vicenza, Italy.
authors.forename: Katia
authors.initials: K
authors.lastname: Chieregato
authors.affiliation: Advanced Cellular Therapy Laboratory, Department of Cellular Therapy and Haematology, San Bortolo Hospital, Vicenza, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Zanon
authors.affiliation: Advanced Cellular Therapy Laboratory, Department of Cellular Therapy and Haematology, San Bortolo Hospital, Vicenza, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Castegnaro
authors.affiliation: Advanced Cellular Therapy Laboratory, Department of Cellular Therapy and Haematology, San Bortolo Hospital, Vicenza, Italy.|Haematology Project Foundation, Vicenza, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Bernardi
authors.affiliation: Advanced Cellular Therapy Laboratory, Department of Cellular Therapy and Haematology, San Bortolo Hospital, Vicenza, Italy.
authors.forename: Eliana
authors.initials: E
authors.lastname: Amati
authors.affiliation: Advanced Cellular Therapy Laboratory, Department of Cellular Therapy and Haematology, San Bortolo Hospital, Vicenza, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Sella
authors.affiliation: Advanced Cellular Therapy Laboratory, Department of Cellular Therapy and Haematology, San Bortolo Hospital, Vicenza, Italy.|Haematology Project Foundation, Vicenza, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Rodeghiero
authors.affiliation: Advanced Cellular Therapy Laboratory, Department of Cellular Therapy and Haematology, San Bortolo Hospital, Vicenza, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Astori
mesh_terms: D019002:CD56 Antigen / Q000032:analysis / Q000276:immunology*; D015550:Cell Degranulation; D002470:Cell Survival; D002478:Cells, Cultured; D055612:Cytokine-Induced Killer Cells / Q000276:immunology* / Q000502:physiology; D016207:Cytokines / Q000276:immunology; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology* / Q000502:physiology; D007951:Leukemia, Myeloid / Q000276:immunology*
chemical_list: D019002:CD56 Antigen; D016207:Cytokines