Pheophorbide A–Mediated Photodynamic Therapy Potentiates Checkpoint Blockade Therapy of Tumor with Low PD–L1 Expression

ABSTRACT: Although the immune checkpoint blockade (ICB) has made a great success in cancer immunotherapy, the overall response rate to the ICB, such as anti–programmed death ligand 1 (PD–L1) therapy, remains only at 20–30%. One major reason is the low expression level of the immune checkpoint in a certain type of tumor cells and its insufficient activation of the host immune system. Herein, we reported a cyclic RGD (cRGD)–modified liposomal delivery system loading the anti–PD–L1 antibody and the photosensitizer pheophorbide A (Pa), allowing a targeting of the low PD–L1 expressing 4T1 mouse breast cancer cells through the recognition of an overexpression of αvβ3 integrin on the tumor cells. The Pa–mediated photodynamic therapy (PDT) elevated the expression of PD–L1 on the tumor cells. PDT, in combina

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PROVIDER: S-EPMC9697200 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature