High-density lipoprotein modulates tumor-associated macrophage for chemoimmunotherapy of hepatocellular carcinoma

Intratumoral abundance of alternatively activated macrophages (M2) in hepatocellular carcinoma (HCC) is associated with advanced stages, poor prognosis and failure of checkpoint blockade immunotherapy. In this work, we discover that synthetic high-density lipoproteins (sHDLs) preferentially deliver cargoes into M2 and Hepa1-6 HCC cells, based on which finding we create a functional sHDL containing esterase-responsive prodrugs of vadimezan and gemcitabine (VG-sHDLs). The VG-sHDLs induce the HCC cells to release damage-associated molecular patterns (high mobility group box 1 protein and ATP) and cytokines including macrophage colony stimulating factor and type I interferons, improving monocyte differentiation into classically activated macrophages (M1) and dendritic cells. Meanwhile, the VG-sHDLs kill M2 without significant toxicity to M1. After intravenous injection, the VG-sHDLs increase intratumoral M1 as well as proinflammatory molecules such as C-X-C motif ligand 9 and 10 and interleukin 12, but reduce M2 and antiinflammatory cytokine interleukin 10. These changes enhance the recruitment and activity of cytotoxic T lymphocytes, which eradicate HCC tumors and also establish tumor-specific immune memory that prevents recurrence. This work sheds light on the interactions between sHDL and intratumoral cells, and provides rationale for chemoimmunotherapy of HCC using conventional chemotherapeutics and emerging immune modulators. (C) 2021 Elsevier Ltd. All rights reserved.