Spleen-Targeting Delivery of the Liposomal Antigen via an RBC-Based Platform for Cancer Immunotherapy

Area of Science:

• Immunology
• Nanotechnology
• Oncology

Background:

• Efficient delivery of tumor antigens to the spleen is crucial for effective systemic cancer vaccination.
• Current nanoparticle-based delivery systems face challenges with reticuloendothelial system sequestration, leading to poor spleen targeting.

Purpose of the Study:

• To develop a novel red blood cell (RBC)-based liposomal antigen delivery system for enhanced spleen targeting.
• To leverage the natural splenic clearance of senescent RBCs for improved vaccine delivery.

Main Methods:

• Covalently conjugating antigen- and adjuvant-loaded liposomes onto the surface of RBCs.
• Inducing senescence-like changes in modified RBCs to enhance splenic sequestration.
• Evaluating spleen accumulation, immune cell uptake, and immune response induction after intravenous administration.

Main Results:

• The RBC-liposome vaccine delivery system demonstrated highly efficient accumulation in the spleen.
• Antigens were effectively internalized by splenic immune cells, leading to robust T cell activation.
• The system achieved a significant tumor inhibition rate of 96.5% in a melanoma mouse model.

Conclusions:

• This RBC-liposome system offers a promising strategy for targeted antigen delivery to the spleen in cancer immunotherapy.
• The approach overcomes limitations of conventional nanoparticle delivery by utilizing RBC senescence for enhanced splenic targeting.
• The study highlights a potential new avenue for developing effective cancer vaccines.