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 alpha-galactosylceramide (alpha GalCer) with sialyl Tn (STn), a representative tumor-associated carbohydrate antigen (TACA). This two component vaccine STn-alpha GalCer is devoid of antigenic peptide, featuring the well-defined structure with high simplicity. STn-alpha GalCer showed remarkable efficacy in inducing antibody class switching from IgM to STn-specific IgG. Subtypes of IgG antibody were primarily IgG1 and IgG3.