IgG Antibody Response Elicited by a Fully Synthetic Two-Component Carbohydrate-Based Cancer Vaccine Candidate with α‑Galactosylceramide as Built-in Adjuvant

A fully synthetic self-adjuvanting cancer vaccine candidate was constructed through covalent conjugation of invariant natural killer T (iNKT) cell ligand α-galactosyl­ceramide (αGalCer) with sialyl Tn (STn), a representative tumor-associated carbohydrate antigen (TACA). This two-component vaccine STn-αGalCer is devoid of antigenic peptide, featuring the well-defined structure with high simplicity. STn-αGalCer showed remarkable efficacy in inducing antibody class switching from IgM to STn-specific IgG. Subtypes of IgG antibody were primarily IgG1 and IgG3.