Research ArticleCancer

Spatially selective depletion of tumor-associated regulatory T cells with near-infrared photoimmunotherapy

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Science Translational Medicine  17 Aug 2016:
Vol. 8, Issue 352, pp. 352ra110
DOI: 10.1126/scitranslmed.aaf6843

Photobombing Tregs

T regulatory cells, or Tregs for short, are immunosuppressive cells that not only suppress excess inflammation but also interfere with anticancer immunity. Sato et al. developed a way to selectively deplete Tregs in tumors to promote antitumor effects while minimizing the risk of autoimmunity. To achieve this goal, the authors used a method termed near-infrared photoimmunotherapy, where part of an antibody that recognizes Tregs is fused to a light-sensitive dye, and shining near-infrared light on the tumor activates the antibody and triggers killing of the Tregs. Mice subjected to this treatment not only killed the targeted tumor but also could even destroy untreated tumors of the same type located in other parts of the body, suggesting the potential for treatment of metastatic disease.