Tumor Antigen on Solid Tumors

Tumor antigens on solid tumors are molecules—often proteins or peptides—expressed at higher levels on the surface of tumor cells compared to normal tissues. These antigens serve as targets for immunotherapies, including chimeric antigen receptor (CAR) T cell and TCR-engineered therapies, aiming to selectively recognize and eliminate cancer cells while sparing healthy tissue. They are broadly classified as Tumor-Associated Antigens (TAAs) which are overexpressed but also present on some normal tissues, and Tumor-Specific Antigens (TSAs)/Neoantigens which are unique to cancer cells. A major challenge is avoiding "on-target off-tumor" toxicity due to shared expression of TAAs on normal tissues. Strategies to improve safety and efficacy include engineering higher affinity receptors, multi-antigen targeting and synthetic biology approaches.

Binding of engineered T cells to tumor antigens, leading to T cell activation and tumor cell lysis.