Photodynamic Therapy and Immune Checkpoint Blockade†. (14th July 2020)

• Record Type: Journal Article
• Authors: Cramer, Gwendolyn M.; Moon, Edmund K.; Cengel, Keith A.; Busch, Theresa M.
• Is Part Of: Photochemistry and photobiology. Volume 96:Number 5(2020)
• Page Start: 954
• Page End: 961
• Publication Date: 2020-07-14
• Subjects: Photochemistry -- Periodicals; Light -- Physiological effect -- Periodicals; 541.35
• DOI: 10.1111/php.13300
• Languages: English
• ISSNs: 0031-8655

Abstract

Abstract: Immune checkpoints including PD‐1 and CTLA‐4 help to regulate the intensity and timeframe of the immune response. Since they become upregulated in cancer and prevent sufficient antitumor immunity, monoclonal antibodies against these checkpoints have shown clinical promise for a range of cancers. Multimodal treatment plans combining immune checkpoint inhibitors with other therapies, including photodynamic therapy (PDT), may help to expand treatment efficacy and minimize side effects. PDT's cytotoxic effects are spatially limited by the light activation process, constraining PDT direct effects to the treatment field. The production of damage‐associated molecular patterns and tumor‐associated antigens from PDT can encourage accumulation and maturation of antigen‐presenting cells and reprogram the tumor microenvironment to be more susceptible to therapies targeting immune checkpoints. Abstract : PDT of a tumor causes direct cell death through various mechanisms, leading to release of antigen and damage‐associated molecular patterns (DAMPs), vasculature damage/platelet aggregation and release of inflammatory cytokines such as IL8 and IL6. This promotes the recruitment of immune cells like neutrophils which then modulate the subsequent immune system response (maturation of dendritic cells and T‐cell activation) that can promote antitumor immunity.