A Glycopeptide Mosaic Vaccine Elicits Robust Antitumor Immunity by Targeting Glycan Heterogeneity.

Aberrantly glycosylated membrane proteins represent promising targets for cancer immunotherapy. However, glycan diversity and heterogeneity pose a challenge to developing effective vaccines against tumors expressing different glycoantigens. To broaden the immune response and enhance the vaccine's efficacy by targeting a wide variety of glycosylation patterns on tumor cells, herein we developed a Mosaic glycopeptide vaccine by simultaneously presenting three different glycopeptides on the carrier protein tetanus toxoid (TT). Immunological evaluation revealed that the Mosaic vaccine elicited higher antibody titers than single-glycopeptide formulations, primarily mediating tumor cell lysis via antibody-dependent cellular cytotoxicity (ADCC) and significantly suppressing tumor growth in both wild-type and transgenic murine models. Notably, the Mosaic vaccine exhibited not only preventive but also therapeutic effects, demonstrating clear antitumor activity in transgenic mice. Combination therapy with PD-1 blockade further enhanced antitumor efficacy. In-depth mechanistic studies demonstrated that the Mosaic vaccine effectively activated antigen-presenting cells and T cells. Furthermore, serum antibodies from Mosaic vaccine-immunized mice exhibited selective binding to patient-derived pancreatic tumor tissues, suggesting their clinical translational potential.