Tumor-specific T-cell receptor (TCR) (TCR)

Tumor-specific T-cell receptors (TCRs) are heterodimeric surface proteins, typically composed of alpha (α) and beta (β) chains, that mediate the recognition of specific peptide fragments presented by Major Histocompatibility Complex (MHC) molecules (UniProt, 2024). Unlike Chimeric Antigen Receptors (CARs) that recognize surface-bound antigens, TCRs can target intracellular proteins—which constitute the majority of the proteome—after they are processed into peptides and presented on the cell surface (Nature Reviews Drug Discovery, 2021). In oncology, these receptors are engineered or selected to recognize tumor-associated antigens (TAAs) like MAGE-A4 or NY-ESO-1, or patient-specific neoantigens resulting from somatic mutations (NCI Dictionary, 2023). Therapeutic applications include TCR-engineered T-cell (TCR-T) therapy, such as the FDA-approved Afamitresgene autoleucel, and soluble bispecific TCR-based engagers like Tebentafusp (FDA, 2022; FDA, 2024). These therapies allow for the redirection of the immune system against solid tumors that may lack suitable surface targets for traditional antibody-based approaches. However, the clinical utility of TCR-based drugs is restricted by the requirement for specific Human Leukocyte Antigen (HLA) types in patients and the risk of off-target toxicity if the target peptide is shared by healthy tissues (Journal of Hematology & Oncology, 2023).

Other names

Tumor-reactive T-cell receptorNeoantigen-specific TCREngineered T-cell receptorTCR complexMHC-restricted T-cell receptorTumor-specific T-cell receptors recognizing MHC-presented tumor-associated antigens and neoantigens

TCR-based therapies function by either engineering a patient's own T cells to express a specific TCR (TCR-T therapy) or by using soluble bispecific molecules (ImmTACs) that bridge a TCR-based recognition domain with an anti-CD3 effector domain, thereby inducing T-cell mediated lysis of tumor cells presenting the target MHC-peptide complex (Nature Reviews Drug Discovery, 2021; FDA, 2022).