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Updated: May 22, 2026
A Novel Feeder-free System for Mass Production of Murine Natural Killer Cells In Vitro
Published on: January 9, 2018
Rapid development of exhaustion and down-regulation of eomesodermin limit the antitumor activity of adoptively
Saar Gill1, Adrianne E Vasey, Alysha De Souza
1Divisions of Blood and Marrow Transplantation, Stanford University, Stanford, CA 94305, USA.
Abstract:
Natural killer (NK) cells are potent anti-viral and antitumor "first responders" endowed with natural cytotoxicity and cytokine production capabilities. To date, attempts to translate these promising biologic functions through the adoptive transfer of NK cells for the treatment of cancer have been of limited benefit. Here we trace the fate of adoptively transferred murine NK cells and make the surprising observation that NK cells traffic to tumor sites yet fail to control tumor growth or improve survival. This dysfunction is related to a rapid down-regulation of activating receptor expression and loss of important effector functions. Loss of interferon (IFN)γ production occurs early after transfer, whereas loss of cytotoxicity progresses with homeostatic proliferation and tumor exposure. The dysfunctional phenotype is accompanied by down-regulation of the transcription factors Eomesodermin and T-bet, and can be partially reversed by the forced overexpression of Eomesodermin. These results provide the first demonstration of NK-cell exhaustion and suggest that the NK-cell first-response capability is intrinsically limited. Further, novel approaches may be required to circumvent the described dysfunctional phenotype.
Insights
Adoptively transferred natural killer (NK) cells fail to control tumors due to rapid functional loss, termed NK-cell exhaustion. This dysfunction, linked to transcription factor downregulation, highlights challenges in cancer immunotherapy.
Area of Science:
- Immunology
- Cancer Biology
- Cellular Therapeutics
Background:
- Natural killer (NK) cells are critical immune cells with inherent cytotoxic and cytokine-producing abilities, important for early anti-viral and anti-tumor responses.
- Despite their potential, adoptive transfer of NK cells for cancer treatment has yielded limited clinical benefits.
- The precise mechanisms underlying the ineffectiveness of transferred NK cells remain incompletely understood.
Purpose of the Study:
- To investigate the in vivo behavior and functional fate of adoptively transferred murine NK cells in a tumor model.
- To identify the molecular and functional changes responsible for the limited efficacy of NK cell adoptive transfer.
- To explore potential strategies for overcoming NK cell dysfunction in the tumor microenvironment.
Main Methods:
- Adoptive transfer of syngeneic NK cells into tumor-bearing mice.
- Tracking of transferred NK cell localization and survival.
- Assessment of NK cell phenotype, including activating receptor expression, cytotoxicity, and cytokine production (IFNγ).
- Analysis of key transcription factors (Eomesodermin, T-bet) and functional recovery via gene overexpression.
Main Results:
- Transferred NK cells successfully trafficked to tumor sites but did not control tumor growth or improve survival.
- NK cells exhibited rapid down-regulation of activating receptors and loss of effector functions, including cytotoxicity and IFNγ production.
- Dysfunction correlated with decreased expression of Eomesodermin and T-bet transcription factors.
- Forced overexpression of Eomesodermin partially restored NK cell function.
Conclusions:
- Adoptively transferred NK cells undergo a rapid "exhaustion" phenotype, characterized by loss of effector functions and altered transcription factor profiles.
- This NK-cell exhaustion represents a significant barrier to effective adoptive immunotherapy for cancer.
- Novel therapeutic strategies are needed to overcome NK cell dysfunction and enhance their anti-tumor efficacy.
