Rationale: Short major histocompatibility class I epitopes can be coupled to the surface of immunogenic liposomes to elicit antigen-specific CD8 + T cells with vaccination.Here, we examined whether the co-incorporation of GM3 ganglioside, a lipid which targets CD169, a sialic acid-binding receptor, would further improve the immunogenicity of this approach.Methods: Liposomes were formed with GM3 incorporated and were assessed for CD169 targeting and anti-tumor immunogenicity in murine models.Antigen-specific CD8 + T cell populations and characteristics were investigated to examine the effect of liposome formulations.Results: GM3 was readily incorporated into immunogenic liposomes and did not interfere with the particle formation with a recently discovered murine renal carcinoma MHC-I neoepitope, Nes2LR.GM3 enhanced the CD169 targeting of liposomes.Immunization with liposomal particles that included GM3 improved antigen-specific CD8 + T cell responses for not only the Nes2LR neoepitope, but for other tumor-associated short MHC-I murine tumor epitopes or mimotopes, including E749-57, and the gp70 mimotope AH1-A5.Immunization of the E7 epitope with GM3 particles induced high-frequency E7-specific CD8 + T cells and effectively reversed the tumor growth of large, established TC-1 tumors as an immune monotherapy.Immunization of the Nes2LR neoepitope in GM3 particles led to delayed tumor growth of RENCA tumors.Conclusion: GM3 ganglioside-containing liposomes that display short peptide epitopes and incorporate immunological adjuvants can be used to elicit potent anti-tumor responses in murine models.Further research is required to further assess the translational potential of this approach.
Zhou et al. (Tue,) studied this question.