Simultaneous Induction of Immunogenic Pyroptosis and PD-L1 Downregulation by One Single Photosensitizer for Synergistic Cancer Photoimmunotherapy.

Pyroptosis, an excellent form of immunogenic cell death that can effectively activate antitumor immune responses, is attracting considerable interest as a promising approach for cancer immunotherapy. Immunogenic pyroptosis can recruit and stimulate dendritic cells to provoke further activation and tumor infiltration of T cells by releasing danger-associated molecular patterns, thus improving the tumor response to PD-1/PD-L1 checkpoint blockade immunotherapy. Here, we report the discovery of a bifunctional photosensitizer Nile Violet that can simultaneously trigger caspase-3/GSDME-mediated immunogenic pyroptosis and PD-L1 downregulation for cancer photoimmunotherapy. It was shown that this synergistic therapeutic strategy significantly inhibited tumor growth by triggering a systemic antitumor immune response. This work highlights the potential of inducing immunogenic pyroptosis and PD-L1 downregulation for synergistic tumor ablation via a single agent.