Near-infrared emitting fluorescent nanocrystals-labeled natural killer cells as a platform technology for the optical imaging of immunotherapeutic cells-based cancer therapy

Nanotechnology. 2009 Nov 25;20(47):475102. doi: 10.1088/0957-4484/20/47/475102. Epub 2009 Oct 29.


This study describes the development of near-infrared optical imaging technology for the monitoring of immunotherapeutic cell-based cancer therapy using natural killer (NK) cells labeled with fluorescent nanocrystals. Although NK cell-based immunotherapeutic strategies have drawn interest as potent preclinical or clinical methods of cancer therapy, there are few reports documenting the molecular imaging of NK cell-based cancer therapy, primarily due to the difficulty of labeling of NK cells with imaging probes. Human natural killer cells (NK92MI) were labeled with anti-human CD56 antibody-coated quantum dots (QD705) for fluorescence imaging. FACS analysis showed that the NK92MI cells labeled with anti-human CD56 antibody-coated QD705 have no effect on the cell viability. The effect of anti-human CD56 antibody-coated QD705 labeling on the NK92MI cell function was investigated by measuring interferon gamma (IFN-gamma) production and cytolytic activity. Finally, the NK92MI cells labeled with anti-human CD56 antibody-coated QD705 showed a therapeutic effect similar to that of unlabeled NK92MI cells. Images of intratumorally injected NK92MI cells labeled with anti-human CD56 antibody-coated could be acquired using near-infrared optical imaging both in vivo and in vitro. This result demonstrates that the immunotherapeutic cells labeled with fluorescent nanocrystals can be a versatile platform for the effective tracking of injected therapeutic cells using optical imaging technology, which is very important in cell-based cancer therapies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / immunology
  • CD56 Antigen / immunology
  • Cell Line
  • Cell Survival
  • Cytotoxicity, Immunologic
  • Female
  • Fluorescence
  • Humans
  • Immunotherapy, Adoptive / methods*
  • Infrared Rays*
  • Killer Cells, Natural / immunology*
  • Mice
  • Mice, Nude
  • Molecular Imaging / methods*
  • Nanoparticles / chemistry*
  • Neoplasms / immunology*
  • Neoplasms / therapy*
  • Quantum Dots
  • Staining and Labeling


  • Antibodies
  • CD56 Antigen