Bionic lipoprotein loaded with chloroquine-mediated blocking immune escape improves antitumor immunotherapy

Area of Science:

• Oncology
• Immunology
• Biomedical Engineering

Background:

• Tumor immunotherapy faces challenges due to immune escape and immunosuppressive tumor microenvironments.
• CD47-SIRPα interaction mediates a "don't eat me" signal, facilitating cancer immune evasion.
• M2-type macrophages in the tumor microenvironment significantly contribute to immune suppression.

Purpose of the Study:

• To develop a novel drug delivery system for enhancing cancer immunotherapy.
• To simultaneously block immune escape pathways and improve the tumor microenvironment.
• To investigate the therapeutic potential of a bionic lipoprotein-based drug delivery system.

Main Methods:

• A drug loading system, BLP-CQ-aCD47, was engineered using bionic lipoprotein (BLP) carriers.
• The system comprises CD47 antibody (aCD47) to block immune escape and chloroquine (CQ) to modulate macrophages.
• BLP facilitated preferential uptake of CQ by M2-type macrophages.

Main Results:

• BLP-CQ-aCD47 effectively reprogrammed M2-type macrophages to M1-type anti-tumor phenotypes.
• The aCD47 component blocked the CD47-SIRPα "don't eat me" signal, enhancing macrophage phagocytosis of tumor cells.
• The combined system demonstrated potential for blocking immune escape and improving the tumor microenvironment.

Conclusions:

• The developed BLP-CQ-aCD47 system offers a promising strategy for cancer immunotherapy.
• This approach simultaneously addresses immune escape and the immunosuppressive tumor microenvironment.
• The system induces a potent anti-tumor immune response with minimal systemic toxicity.