T-cell receptor alpha-beta (TCR) (TCR)

The T-cell receptor (TCR) is a multi-subunit protein complex found on the surface of T lymphocytes, primarily composed of alpha (α) and beta (β) chains (StatPearls, 2023). It is responsible for recognizing processed antigenic peptides presented by Major Histocompatibility Complex (MHC) molecules, a fundamental step in the adaptive immune response (UniProt, 2024). In oncology, TCRs on CD8+ and CD4+ T cells are utilized as therapeutic targets through TCR-engineered T-cell (TCR-T) therapies and bispecific molecules like ImmTACs (Nature Reviews Drug Discovery, 2022). These approaches allow the immune system to target intracellular proteins, such as MAGE-A4 or NY-ESO-1, which are presented as surface MHC-peptide complexes, thereby expanding the range of targetable antigens beyond those accessible to traditional antibodies (PubMed, 2021). Therapeutic agents like Afamitresgene autoleucel and Tebentafusp leverage this mechanism to treat solid tumors, though they require specific HLA matching and carry risks of cytokine release syndrome and off-target toxicities (FDA, 2024; Journal of Hematology & Oncology, 2023). The specificity of the TCR for its cognate peptide-MHC complex is the key determinant of both the efficacy and the safety profile of these immunotherapies (Cell, 2022).

Other names

T-cell antigen receptorTCR complexTCR alpha-betaCD3-TCR complexT-cell receptor

Engineered TCRs or bispecific molecules facilitate the recognition of specific peptide-MHC complexes on target cells, leading to T-cell activation and targeted cytotoxicity.