Enhanced expression of natural cytotoxicity receptors on cytokine-induced memory-like natural killer cells correlates with effector function

Front Immunol. 2023 Oct 16:14:1256404. doi: 10.3389/fimmu.2023.1256404. eCollection 2023.

Abstract

Introduction: Natural killer (NK) cells are a key component of the innate immune system, involved in defending the host against virus-infected cells and tumor immunosurveillance. Under in vitro culture conditions, IL-12/15/18 can induce a memory-like phenotype in NK cells. These cytokine-induced memory-like (CIML) NK cells possess desirable characteristics for immunotherapies, including a longer lifespan and increased cytotoxicity.

Methods: In this study, NK cells were isolated from peripheral blood of healthy donors and stimulated with IL-12/15/18 to induce a memory-like phenotype or with IL-15 alone as a control. After seven days of culture, multiparametric flow cytometry analysis was performed to evaluate the phenotypic and functional profiles of CIML and control NK cells.

Results: Our results showed a significantly higher expression of CD25, CD69, NKG2D, NKp30, NKp44, NKp46, TACTILE, and Granzyme B in CIML NK cells compared to control NK cells. In contrast, KIR2D expression was significantly lower in CIML NK cells than in control NK cells. Moreover, functional experiments demonstrated that CIML NK cells displayed enhanced degranulation capacity and increased intracellular IFN-γ production against the target cell line K562. Interestingly, the degranulation capacity of CIML NK cells was positively correlated with the expression of the activating receptors NKp46 and NKp30, as well as with the inhibitory receptor TACTILE.

Discussion: In conclusion, this study provides a deep phenotypic characterization of in vitro-expanded CIML NK cells. Moreover, the correlations found between NK cell receptors and degranulation capacity of CIML NK cells allowed the identification of several biomarkers that could be useful in clinical settings.

Keywords: NK cells; NKG2D; cancer immunotherapy; cytokine-induced memory-like NK cells; degranulation capacity; memory-like; natural cytotoxicity receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytokines* / metabolism
  • Flow Cytometry
  • Interleukin-12 / metabolism
  • Killer Cells, Natural*
  • Receptors, Natural Killer Cell / metabolism

Substances

  • Cytokines
  • Receptors, Natural Killer Cell
  • Interleukin-12

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by grants GR21178 to Group “Inmunopatología Tumoral” and research project IB20132 funded by Consejeria de Economia, Ciencia y Agenda Digital (now Consejería de Educación, Ciencia y Formación Profesional) from Junta de Extremadura and co-funded by the European Union (to RT); Project PI21/01125 (to RS), and PI19/00075 (to AP) funded by Instituto de Salud Carlos III (ISCIII) and co-funded by the European Union and PECART 0060-2020 (to RS) from Secretaría General de Investigación, Desarrollo e Innovación en Salud, Junta de Andalucía, Spain. All co-financed by the European Union, European Regional Development Fund (FEDER) “Una manera de hacer Europa”. Employment promotion program for the hiring of research support personnel (reference TE-0032-21 to MGS) from Consejería de Educación y Empleo, Junta de Extremadura and postdoctoral fellowship (reference DOC_01421 to FH) from Regional Ministry of Economic Transformation, Industry, Knowledge, and Universities of the Junta de Andalucía, both co-financed by the European Social Fund (ESF) under the Youth Employment Operational Programme 2014-2020. “The ESF invests in your future”.