Advanced Cancer Immunotherapy via SMARCAL1 Blockade Using a Glucose-Responsive CRISPR Nanovaccine.

Abstract

Cancer immunotherapy that activates the stimulator of interferon genes (STING) signaling pathway to resist tumors has recently attracted considerable attention. However, STING activation can induce opposing interferon functions that contribute to T-cell exhaustion via programmed death-ligand 1 (PD-L1). In particular, effectively using the immune system to combat tumors remains a substantial challenge due to tumor immunosuppressive factors such as SMARCAL1. Here, a glucose-responsive CRISPR nanovaccine is developed for enhancing STING signaling while inhibiting interferon-mediated immunosuppressive feedback. The formulation encapsulates a bimetallic zeolitic imidazolate framework with glucose oxidase (GOx) and CRISPR-mediated SMARCAL1 gene-editing plasmids. The dual enzyme-driven cascade reactions of peroxidase and GOx generate reactive oxygen species (ROS) and gluconic acid, which release and activate the genome-editing system. The silencing of SMARCAL1 enhances STING activity and inhibits PD-L1 expression, resulting in the termination of PD-L1-mediated opposing functions of interferon. Zinc ions and double-stranded DNA formed via ROS further activate the STING pathway, effectively inducing dendritic cell maturation and immune system activation. This is a critical report of in situ CRISPR nanovaccination driven by dual enzymes. The work highlights the potential of glucose-responsive CRISPR nanovaccination in bolstering antitumor immunity and extends the implementation of gene editing in cancer immunotherapy.