Genetically re-engineered K562 cells significantly expand and functionally activate cord blood natural killer cells: Potential for adoptive cellular immunotherapy

Exp Hematol. 2017 Feb;46:38-47. doi: 10.1016/j.exphem.2016.10.003. Epub 2016 Oct 17.


Natural killer (NK) cells play a significant role in reducing relapse in patients with hematological malignancies after allogeneic stem cell transplantation, but NK cell number and naturally occurring inhibitory signals limit their capability. Interleukin-15 (IL-15) and 4-1BBL are important modulators of NK expansion and functional activation. To overcome these limitations, cord blood mononuclear cells (CB MNCs) were ex vivo expanded for 7 days with genetically modified K562-mbIL15-41BBL (MODK562) or wild-type K562 (WTK562). NK cell expansion; expression of lysosome-associated membrane protein-1 (LAMP-1), granzyme B, and perforin; and in vitro and in vivo cytotoxicity against B-cell non-Hodgkin lymphoma (B-NHL) were evaluated. In vivo tumor growth in B-NHL-xenografted nonobese diabetic severe combined immune deficient (NOD-scid) gamma (NSG) mice was monitored by tumor volume, cell number, and survival. CB MNCs cultured with MODK562 compared with WTK562 demonstrated significantly increased NK expansion (thirty-fivefold, p < 0.05); LAMP-1 (p < 0.05), granzyme B, and perforin expression (p < 0.001); and in vitro cytotoxicity against B-NHL (p < 0.01). Xenografted mice treated with MODK562 CB experienced significantly decreased B-NHL tumor volume (p = 0.0086) and B-NHL cell numbers (p < 0.01) at 5 weeks and significantly increased survival (p < 0.001) at 10 weeks compared with WTK562. In summary, MODK562 significantly enhanced CB NK expansion and cytotoxicity, enhanced survival in a human Burkitt's lymphoma xenograft NSG model, and could be used in the future as adoptive cellular immunotherapy after umbilical CB transplantation. Future directions include expanding anti-CD20 chimeric receptor-modified CB NK cells to enhance B-NHL targeting in vitro and in vivo.

MeSH terms

  • Animals
  • Biomarkers
  • Cell Communication
  • Cell Culture Techniques
  • Cell Engineering*
  • Cell Line, Tumor
  • Cell Survival
  • Cytotoxicity, Immunologic
  • Fetal Blood / cytology*
  • Genetic Engineering*
  • Granzymes / metabolism
  • Heterografts
  • Humans
  • Immunotherapy, Adoptive / methods
  • K562 Cells / metabolism*
  • Killer Cells, Natural / immunology*
  • Killer Cells, Natural / metabolism*
  • Leukocytes, Mononuclear
  • Lymphocyte Activation / immunology
  • Lysosomal-Associated Membrane Protein 1 / metabolism
  • Mice
  • Mice, Knockout
  • Perforin / metabolism
  • Receptors, Natural Killer Cell / metabolism
  • Xenograft Model Antitumor Assays


  • Biomarkers
  • Lysosomal-Associated Membrane Protein 1
  • Receptors, Natural Killer Cell
  • Perforin
  • Granzymes