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An In-House-Built and Light-Emitting-Diode-Based Photodynamic Therapy Device for Enhancing Verteporfin Cytotoxicity in a 2D Cell Culture Model
Published on: January 13, 2023
Photodynamic therapy: illuminating the road from cell death towards anti-tumour immunity
Abhishek D Garg1, Dominika Nowis, Jakub Golab
1Department of Molecular Cell Biology, Catholic University of Leuven, Belgium.
Abstract:
Photodynamic therapy (PDT) utilizes the destructive power of reactive oxygen species generated via visible light irradiation of a photosensitive dye accumulated in the cancerous tissue/cells, to bring about their obliteration. PDT activates multiple signalling pathways in cancer cells, which could give rise to all three cell death modalities (at least in vitro). Simultaneously, PDT is capable of eliciting various effects in the tumour microenvironment thereby affecting the tumour-associated/-infiltrating immune cells and by extension, leading to infiltration of various immune cells (e.g. neutrophils) into the treated site. PDT is also associated to the activation of different immune phenomena, e.g. acute-phase response, complement cascade and production of cytokines/chemokines. It has also come to light that, PDT is capable of activating 'anti-tumour adaptive immunity' in both pre-clinical as well as clinical settings. Although the ability of PDT to induce 'anti-cancer vaccine effect' is still debatable, yet it has been shown to be capable of inducing exposure/release of certain damage-associated molecular patterns (DAMPs) like HSP70. Therefore, it seems that PDT is unique among other approved therapeutic procedures in generating a microenvironment suitable for development of systemic anti-tumour immunity. Apart from this, recent times have seen the emergence of certain promising modalities based on PDT like-photoimmunotherapy and PDT-based cancer vaccines. This review mainly discusses the effects exerted by PDT on cancer cells, immune cells as well as tumour microenvironment in terms of anti-tumour immunity. The ability of PDT to expose/release DAMPs and the future perspectives of this paradigm have also been discussed.
Insights
Photodynamic therapy (PDT) harnesses light-activated dyes to destroy cancer cells and stimulate systemic anti-tumour immunity. This approach uniquely reprograms the tumor microenvironment, enhancing immune responses against cancer.
Area of Science:
- Immunology
- Oncology
- Photochemistry
Background:
- Photodynamic therapy (PDT) uses photosensitizers and light to generate reactive oxygen species, leading to cancer cell death.
- PDT influences cancer cell signaling pathways, potentially inducing various cell death modalities.
- PDT impacts the tumor microenvironment, affecting immune cells and promoting immune responses.
Purpose of the Study:
- To review the multifaceted effects of PDT on cancer cells, immune cells, and the tumor microenvironment.
- To explore PDT's role in stimulating anti-tumor immunity, including adaptive immunity.
- To discuss emerging PDT-based modalities and their potential in cancer therapy.
Main Methods:
- Review of existing literature on photodynamic therapy and anti-tumor immunity.
- Analysis of PDT's effects on cancer cell death pathways.
- Examination of PDT's influence on immune cell infiltration and activation within the tumor microenvironment.
Main Results:
- PDT induces cancer cell death and activates immune phenomena like cytokine production and complement cascade.
- PDT promotes the infiltration of immune cells, such as neutrophils, into the tumor site.
- PDT can activate anti-tumor adaptive immunity and induce the release of damage-associated molecular patterns (DAMPs).
Conclusions:
- PDT uniquely creates a pro-immunity tumor microenvironment conducive to systemic anti-tumor responses.
- Emerging PDT-based strategies like photoimmunotherapy and cancer vaccines show promise.
- Further research into PDT's immunomodulatory effects could lead to novel cancer treatment paradigms.
