Dual-Synergistic Nanomodulator Alleviates Exosomal PD-L1 Expression Enabling Exhausted Cytotoxic T Lymphocytes Rejuvenation for Potentiated iRFA-Treated Hepatocellular Carcinoma Immunotherapy.

Abstract

The tumor immunosuppressive microenvironment (TME) induced by incomplete radiofrequency ablation (iRFA) in hepatocellular carcinoma (HCC) is a critical driver of tumor progression and metastasis. Herein, we proposed a therapeutic strategy aimed at remodeling the post-iRFA TME by targeting exosome biogenesis, secretion, and PD-L1 expression, thereby rejuvenating cytotoxic T lymphocyte function to mitigate the progression and metastasis of HCC. Leveraging the versatile properties of polydopamine nanomodulators, we have engineered a tailored delivery platform for GW4869 and amlodipine (AM), enabling precise and tumor-specific release of these therapeutic agents. Initially, GW4869, a neutral sphingomyelinase inhibitor, synergized with AM, an intracellular calcium modulator, to suppress exosome biogenesis and secretion. Subsequently, AM triggered the autophagic degradation of PD-L1. <i>In vitro</i> and <i>in vivo</i> experiments demonstrated that this synergistic approach significantly enhanced the robust activation and proliferation of various functional T-cell subsets following iRFA, particularly CD8⁺T cells, IFN-γ⁺ CD8⁺ cytotoxic T cells, natural killer cells, and innate lymphoid cells. Concurrently, it effectively reduced the infiltration of immunosuppressive cell types, including regulatory T cells and myeloid-derived suppressor cells. This favorable remodeling of the TME substantially inhibited the progression and metastasis of HCC post-iRFA. Collectively, our study presented a promising paradigm for enhancing HCC treatment efficacy by integrating radiofrequency ablation with advanced immune modulation strategies.