Liposomal Nanovaccine Containing α-Galactosylceramide and Ganglioside GM3 Stimulates Robust CD8+ T Cell Responses via CD169+ Macrophages and cDC1

Successful anti-cancer vaccines aim to prime and reinvigorate cytotoxic T cells and should therefore comprise a potent antigen and adjuvant. Antigen targeting to splenic CD169(+) macrophages was shown to induce robust CD8(+) T cell responses via antigen transfer to cDC1. Interestingly, CD169(+) macrophages can also activate type I natural killer T-cells (NKT). NKT activation via ligands such as alpha-galactosylceramide (alpha GC) serve as natural adjuvants through dendritic cell activation. Here, we incorporated ganglioside GM3 and alpha GC in ovalbumin (OVA) protein-containing liposomes to achieve both CD169(+) targeting and superior DC activation. The systemic delivery of GM3-alpha GC-OVA liposomes resulted in specific uptake by splenic CD169(+) macrophages, stimulated strong IFN gamma production by NKT and NK cells and coincided with the maturation of cDC1 and significant IL-12 production. Strikingly, superior induction of OVA-specific CD8(+) T cells was detected after immunization with GM3-alpha GC-OVA liposomes. CD8(+) T cell activation, but not B cell activation, was dependent on CD169(+) macrophages and cDC1, while activation of NKT and NK cells were partially mediated by cDC1. In summary, GM3-alpha GC antigen-containing liposomes are a potent vaccination platform that promotes the interaction between different immune cell populations, resulting in strong adaptive immunity and therefore emerge as a promising anti-cancer vaccination strategy.

Automated summary

Successful anti-cancer vaccines targeting cytotoxic T cells and immune cell interactions through GM3-alpha GC-OVA liposomes show promising results in inducing strong adaptive immunity against cancer. The activation of CD8(+) T cells, NKT, and NK cells plays a critical role in the potent immune response, highlighting the potential of this vaccine platform for anti-cancer strategies.