Enhanced Immune Response Against the Thomsen-Friedenreich Tumor Antigen Using a Bivalent Entirely Carbohydrate Conjugate

Molecules. 2020 Mar 13;25(6):1319. doi: 10.3390/molecules25061319.


The Thomsen-Friedenreich (TF) antigen is a key target for the development of anticancer vaccines, and this ongoing challenge remains relevant due to the poor immunogenicity of the TF antigen. To overcome this challenge, we adopted a bivalent conjugate design which introduced both the TF antigen and the Thomsen-nouveau (Tn) antigen onto the immunologically relevant polysaccharide A1 (PS A1). The immunological results in C57BL/6 mice revealed that the bivalent, Tn-TF-PS A1 conjugate increased the immune response towards the TF antigen as compared to the monovalent TF-PS A1. This phenomenon was first observed with enzyme-linked immunosorbent assay (ELISA) where the bivalent conjugate generated high titers of IgG antibodies where the monovalent conjugate generated an exclusive IgM response. Fluorescence-activated cell sorting (FACS) analysis also revealed increased binding events to the tumor cell lines MCF-7 and OVCAR-5, which are consistent with the enhanced tumor cell lysis observed in a complement dependent cytotoxicity (CDC) assay. The cytokine profile generated by the bivalent construct revealed increased pro-inflammatory cytokines IL-17 and IFN-γ. This increase in cytokine concentration was matched with an increase in cytokine producing cells as observed by ELISpot. We hypothesized the mechanisms for this phenomenon to involve the macrophage galactose N-acetylgalactosamine specific lectin 2 (MGL2). This hypothesis was supported by using biotinylated probes and recombinant MGL2 to measure carbohydrate-protein interactions.

Keywords: C-type lectin receptor; cancer vaccine; multivalent vaccine; tumor associated carbohydrate antigen; zwitterionic polysaccharide.

MeSH terms

  • Animals
  • Antibodies / metabolism
  • Antibody Specificity / immunology
  • Antigens, Tumor-Associated, Carbohydrate / immunology*
  • Biotinylation
  • Carbohydrates / chemical synthesis
  • Carbohydrates / chemistry
  • Carbohydrates / immunology*
  • Cell Line, Tumor
  • Complement System Proteins / metabolism
  • Cytokines / metabolism
  • Cytotoxicity, Immunologic
  • Humans
  • Immunity*
  • Immunoconjugates / chemistry
  • Immunoconjugates / immunology*
  • Lectins, C-Type / metabolism
  • Male
  • Mice, Inbred C57BL
  • Recombinant Proteins / metabolism
  • Spleen / immunology


  • Antibodies
  • Antigens, Tumor-Associated, Carbohydrate
  • Carbohydrates
  • Cytokines
  • Immunoconjugates
  • Lectins, C-Type
  • MGL2 protein, mouse
  • Recombinant Proteins
  • Thomsen-Friedenreich antigen
  • Complement System Proteins