Syntheses and Immunological Evaluation of Self‐Adjuvanting Clustered N‐Acetyl and N‐Propionyl Sialyl‐Tn Combined with a T‐helper Cell Epitope as Antitumor Vaccine Candidates

Sialyl‐Tn (STn) is a tumor‐associated carbohydrate antigen (TACA) rarely observed on healthy tissues. We synthesized two fully synthetic N‐acetyl and N‐propionyl STn trimer (triSTn) vaccines possessing a T‐helper epitope and a TLR2 agonist, since the clustered STn antigens are highly expressed on many cancer cells. Immunization of both vaccines in mice induced the anti‐triSTn IgG antibodies, which recognized triSTn‐expressing cell lines PANC‐1 and HepG2. The N‐propionyl triSTn vaccine induced the triSTn‐specific IgGs, while IgGs induced by the N‐acetyl triSTn vaccine were less specific. These results illustrated that N‐propionyl triSTn is a valuable unnatural TACA for anticancer vaccines. Effektive Anti‐STn‐Antikörper wurden durch zwei vollsynthetische N‐Acetyl‐ und N‐Propionyl‐triSTn‐Vakzine erzeugt, einschließlich eingebautem T‐Helfer‐Epitop und Adjuvans. Das N‐Propionyl‐triSTn‐Vakzin ruft eine triSTn‐spezifische Immunantwort hervor.