Mannose-modified liposome designed for epitope peptide drug delivery in cancer immunotherapy

Based on the interaction between cytotoxic T lymphocyte (CTL) dominant epitopes and dendritic cells (DCs), CD8+T cells are specifically activated into CTL cells. Targeted killing is a type of tumor vaccine for immunotherapy with great development potential. However, because of the disadvantages of poor stability in vivo and low uptake rate of DCs caused by single use of dominant epitope peptide drugs, its use is limited. Here, we investigated the antitumor potential of M-YL/LA-Lipo, a novel liposome drug delivery system.We assembled mannose on the surface of liposome, which has a highly targeted effect on the mannose receptor on the surface of DCs. The dominant epitope peptide drugs were encapsulated into the liposome using membrane hydration method, and the encapsulation rate, release rate, in vitro stability, and microstructure were characterized using ultrafiltration method, dialysis method, and negative staining transmission electron microscopy. In addition, its targeting ability was verified by in vitro interaction with DCs, and its anticancer effect was verified by animal experiments.We have successfully prepared a liposome drug delivery system with stable physical and chemical properties. Moreover, we demonstrated that it was highly uptaken by DCs and promoted DC maturation in vitro. Furthermore, in vivo animal experiments indicated that M-YL/LA-Lipo specific CTL significantly inhibited the hematogenous spread of lung metastasis of triple negative breast cancer.we successfully constructed a new polypeptide liposome drug delivery system by avoiding the disadvantages of single use of dominant epitope peptide drugs and accurate targeted therapy for tumors.