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Measurement of Natural Killer Cell-Mediated Cytotoxicity and Migration in the Context of Hepatic Tumor Cells
06:55

Measurement of Natural Killer Cell-Mediated Cytotoxicity and Migration in the Context of Hepatic Tumor Cells

Published on: February 22, 2020

Hypoxia downregulates the expression of activating receptors involved in NK-cell-mediated target cell killing without

Mirna Balsamo1, Claudia Manzini, Gabriella Pietra

  • 1Dipartimento di Medicina Sperimentale, Università di Genova, Genova, Italy.

European Journal of Immunology
|August 6, 2013
PubMed

Insights

Hypoxia impairs natural killer (NK) cell anti-tumor activity by reducing activating receptor expression. However, NK cells retain antibody-dependent cellular cytotoxicity via CD16, offering potential for cancer immunotherapy.

Area of Science:

  • Immunology
  • Cancer Biology
  • Cellular Microenvironments

Background:

  • Hypoxia disrupts homeostasis in infection sites and tumors, altering immune cell function and promoting disease.
  • Natural killer (NK) cells combat virus-infected and transformed cells, but their response to hypoxia remains unclear.

Purpose of the Study:

  • To investigate the impact of hypoxia on NK cell function and phenotype.
  • To explore the potential of NK cells in antibody-based cancer immunotherapy under hypoxic conditions.

Main Methods:

  • Analysis of NK cell adaptation to hypoxia via hypoxia-inducible factor 1α (HIF-1α) upregulation.
  • Assessment of NK cell receptor expression (NKp46, NKp30, NKp44, NKG2D, CD16) and cytokine responsiveness (IL-2, IL-15, IL-12, IL-21).
  • Evaluation of NK cell killing capacity against target cells in hypoxic conditions, including antibody-dependent cellular cytotoxicity (ADCC).

Main Results:

  • NK cells upregulate HIF-1α in response to hypoxia, indicating adaptation.
  • Hypoxia impairs NK cell ability to upregulate key activating receptors (NKp46, NKp30, NKp44, NKG2D) upon cytokine stimulation.
  • Reduced activating receptor expression correlates with diminished NK cell killing of infected or tumor cells.
  • Hypoxia does not significantly affect the surface density or function of the Fc-γ receptor CD16.
  • NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC) is preserved in hypoxic environments.

Conclusions:

  • Hypoxia alters NK cell phenotype and function, reducing their direct cytotoxic activity.
  • Preserved CD16 function allows NK cells to maintain ADCC in hypoxic tumor microenvironments.
  • Targeting CD16-mediated ADCC offers a promising strategy for antibody-based cancer immunotherapy in hypoxic tumors.
Keywords:
ADCCHypoxiaNK cellsTumor EscapeTumor Microenvironment

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