"Trojan horse" nanoparticle-delivered cancer cell membrane vaccines to enhance cancer immunotherapy by overcoming immune-escape.

Cancer cell membranes (CCMs) have emerged as advanced cancer treatment vaccines to boost the immune response against cancer and have shown great potential in cancer immunotherapy. However, the CCM vaccine confronts the challenges of a weak and short immune response, ascribed to the immune escape and low accumulation of the CCM in antigen presentation cells (APCs). To overcome these shortcomings, we devised a "Trojan horse" CCM nano-vaccine delivered by layered double hydroxide (LDH) nanoparticles with mannose targeting and bovine serum albumin (BSA) coating to overcome the immune escape challenge, efficiently boosting the immune response to cancer cells. This "Trojan horse" CCM nano-vaccine, named LGCMB, is constructed by assembling the CCM antigen on CpG-LDH (LG), followed by mannose-BSA coating for the APC target and BSA coating to mask immune-escape protein on the CCM. The in vitro cellular uptake and maturation data have clearly shown that the BSA coating strategy with mannose as a "Trojan horse" efficiently targeted APCs (macrophages and DCs) and effectively inhibited the immune escape of the CCM, competently stimulating the APC maturation. Moreover, LGCMB can migrate to the draining lymph nodes (LNs) and trigger tumor-specific CD8+ T cell responses in vivo. As expected, the LGCMB nano-vaccine significantly suppressed tumor growth in vivo, showing great potential as a precision cancer vaccine.