Thomsen-Friedenreich antigen (CD176) (TF antigen)

The Thomsen-Friedenreich (TF) antigen, also designated as CD176, is a prominent tumor-associated carbohydrate antigen (TACA) characterized by the disaccharide structure Galbeta1-3GalNAcalpha1-O-Ser/Thr (Springer, 1984). Under physiological conditions, the TF antigen is a cryptic structure, typically masked by terminal sialic acid residues on normal cell surfaces; however, in approximately 80-90% of human adenocarcinomas, truncated O-glycosylation leads to its exposure and overexpression (Heimburg-Molinaro et al., 2011). Biologically, the TF antigen facilitates cancer progression and metastasis by serving as a ligand for galectins, specifically Galectin-3, which promotes the adhesion of tumor cells to the vascular endothelium and helps form tumor cell clusters in circulation (Glinsky et al., 2001). Therapeutic interventions targeting CD176 include monoclonal antibodies like hJAA-F11 and various glycan-based vaccines designed to stimulate the immune system to recognize and eliminate TF-expressing malignant cells (Rittenhouse-Olson, 2007). Given its restricted expression on healthy tissues and high prevalence in cancers such as breast, lung, and prostate, it remains a significant target for both immunotherapy and diagnostic imaging.

Other names

T antigenCore 1 O-glycanGal-GalNAcCD176Galbeta1-3GalNAcalpha1-Ser/Thr

Monoclonal antibodies targeting the TF antigen induce tumor cell death via antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), while also blocking the interaction between the TF antigen and circulating galectins to inhibit metastatic seeding. Carbohydrate-based vaccines aim to elicit high-titer IgG antibodies that recognize the TF structure on malignant cells.