Tumor cell surface antigens (TAA)

Tumor cell surface antigens (TAAs) are a diverse group of molecules, including proteins, glycoproteins, and glycolipids, that are overexpressed or aberrantly expressed on the plasma membrane of malignant cells [Abbas et al., Cellular and Molecular Immunology]. When therapeutic monoclonal antibodies bind to these antigens, the tumor cell becomes opsonized, effectively tagged for recognition by the immune system. This opsonization allows the Fc portion of the antibody to engage Fc gamma receptors (FcγRs) on effector cells such as Natural Killer (NK) cells and macrophages, triggering Antibody-Dependent Cellular Cytotoxicity (ADCC) and Antibody-Dependent Cellular Phagocytosis (ADCP) [Nimmerjahn & Ravetch, 2008, Nature Reviews Immunology]. Additionally, the bound antibodies can initiate the classical complement pathway, leading to the formation of the membrane attack complex and Complement-Dependent Cytotoxicity (CDC) [Weiner et al., 2010, Nature Reviews Immunology]. This multi-pronged immune attack is the primary mechanism for many blockbuster oncology drugs, though its efficacy can be influenced by antigen density and host genetic factors like FcγR polymorphisms. Targeting these antigens allows for the selective elimination of malignant cells, although off-tumor effects on healthy tissues expressing the same antigens remain a significant clinical challenge.

Other names

Tumor-associated antigensTumor-specific antigensTSASurface-expressed tumor antigensOpsonized tumor antigens

Monoclonal antibodies bind to tumor cell surface antigens, opsonizing the cell and triggering immune-mediated destruction via Antibody-Dependent Cellular Cytotoxicity (ADCC), Antibody-Dependent Cellular Phagocytosis (ADCP), and Complement-Dependent Cytotoxicity (CDC).