Tumor-derived antigen (TAA)

Tumor-derived antigens at the ablation site refer to the diverse array of proteins, neoantigens, and cellular debris released into the local microenvironment following the physical destruction of a tumor via methods such as radiofrequency ablation, cryoablation, or microwave ablation (Chu & Goldberg, 2019). This process, often termed 'in situ vaccination,' transforms the tumor site into a source of immunogenic material that can be recognized by the host's immune system (Van den Eynde, 2018). When tumor cells undergo necrosis, they release not only specific antigens but also damage-associated molecular patterns (DAMPs) like HMGB1 and heat shock proteins, which act as endogenous adjuvants to activate dendritic cells (Kroemer et al., 2013). These dendritic cells then capture the released antigens and migrate to regional lymph nodes to prime cytotoxic T lymphocytes, potentially leading to a systemic anti-tumor response known as the abscopal effect. While the ablation site itself provides the raw material for an immune response, the effect is often insufficient to overcome tumor-induced immunosuppression on its own. Consequently, this 'target' is frequently leveraged in combination therapies with immune checkpoint inhibitors or toll-like receptor agonists to enhance the breadth and durability of the resulting immune attack against both local and metastatic disease.

Other names

Tumor-associated antigenNeoantigenIn situ vaccine antigenAblation-released antigenDamage-associated molecular pattern (DAMP)

In situ vaccination: Thermal or mechanical ablation induces tumor cell necrosis, releasing a pool of tumor-specific antigens and danger signals that prime the immune system against the cancer (Chu & Goldberg, 2019).