A Liposomal Nanovaccine Reprograms Post-Ablation Macrophages to Sustain Antitumor Immunity in Hepatocellular Carcinoma.

Abstract

Incomplete radiofrequency ablation (iRFA) of hepatocellular carcinoma frequently results in tumor recurrence driven by residual tumor cells and an immunosuppressive microenvironment dominated by M2 macrophages. Although RFA transiently stimulates antitumor immunity through tumor antigen release, post-ablation efferocytosis of apoptotic tumor cells reinforces immune tolerance and limits durable responses. Here, we report a multifunctional liposomal nano-vaccine (R/B@Lipo-I, composed of the MerTK inhibitor BMS777607, the TLR7/8 agonist R848, and surface-anchored interferon-γ) to overcome post-RFA immunosuppression by inhibiting efferocytosis while promoting macrophage M1 polarization. Mechanistically, BMS777607 suppressed efferocytosis, converting apoptotic tumor cells into immunogenic signals, whereas R848 and interferon-γ activated NF-κB and JAK-STAT pathways to drive pro-inflammatory macrophage reprogramming. In vitro, R/B@Lipo-I induced M1 polarization, enhanced phagocytic and antigen-presenting functions, and promoted dendritic cell maturation and CD8⁺ T-cell activation. In vivo, it significantly potentiated RFA efficacy, suppressed tumor growth, and remodeled the tumor immune microenvironment by increasing M1 macrophages, mature dendritic cells, and cytotoxic T cells while reducing M2 macrophages and regulatory T cells. Transcriptomic analyses further confirmed activation of interferon-γ-responsive, TNF-related, and innate immune pathways. Collectively, this work establishes macrophage reprogramming via efferocytosis inhibition as an effective strategy to overcome RFA-induced immunosuppression and provides a rational nanotherapeutic approach to reduce tumor recurrence. STATEMENT OF SIGNIFICANCE: Incomplete radiofrequency ablation leaves behind an immunosuppressive tumor niche that conventional therapies fail to overcome. We demonstrate a rationally engineered liposomal nano-vaccine that hijacks apoptotic tumor signals, rewires macrophages toward a pro-inflammatory state, and orchestrates a systemic anti-tumor immune response. This strategy transforms post-ablation immune tolerance into durable immunity, offering a mechanistically guided approach to prevent tumor recurrence and advance nanomedicine-based cancer immunotherapy.