Assessing the Impact of Phytochemicals on Immune Checkpoints: Implications for Cancer Immunotherapy

  • Melanie R. Power Coombs
  • David W. HoskinEmail author
Part of the Methods in Molecular Biology book series (MIMB, volume 2111)


Phytochemicals are the basis for many anticancer drugs currently in clinical use, as well as a potential source of future cancer treatments. Some phytochemicals have been found to modify the expression of checkpoint inhibitors of the immune response, as well as kill cancer cells. Cancer cells, in turn, may evade detection by the immune system by expressing molecules such as programmed death ligand 1 (PD-L1) that interacts with programmed cell death 1 (PD-1) on T cells to inhibit T cell activation and effector function. Phytochemicals have direct effects on cancer cells and/or T cells that may impact PD-L1/PD1 interactions, although this may vary depending on the phytochemical in question. Flow cytometric analysis of cancer cells stained with anti-PD-L1 antibodies following treatment with a given phytochemical enables the detection of any alteration in PD-L1 expression. The effect of the phytochemical on T cell function can be assessed using proliferation assays (e.g., tritiated thymidine incorporation, flow cytometric analysis of Oregon Green 488-stained cells) and enzyme-linked immunosorbent assay of interleukin-2 content in culture supernatants. Additional study is needed to better understand the impact of phytochemicals on cancer immunotherapy.

Key words

Cancer Co-cultures Flow cytometry Immune checkpoints Immunotherapy Interleukin-2 Proliferation T cells 


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© Springer Science+Business Media, LLC, part of Springer Nature 2020

Authors and Affiliations

  1. 1.Department of BiologyAcadia UniversityWolfvilleCanada
  2. 2.Department of Microbiology and ImmunologyDalhousie UniversityHalifaxCanada
  3. 3.Department of PathologyDalhousie UniversityHalifaxCanada
  4. 4.Department of SurgeryDalhousie UniversityHalifaxCanada

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