T cell receptor alpha-beta chain (TCRαβ)

The T cell receptor alpha-beta chain is the principal antigen receptor on the surface of most T lymphocytes, composed of a heterodimer of one alpha (α) and one beta (β) chain. These chains together form the antigen-binding site that recognizes peptides presented by major histocompatibility complex (MHC) molecules on other cells. In TCR gene-engineered T cell therapies, T cells are genetically modified to express new, tumor- or virus-specific alpha-beta TCRs, redirecting T cell specificity and effector function against target cells. The alpha and beta chains are both members of the immunoglobulin superfamily, each containing variable and constant regions; extensive diversity is generated by V(D)J recombination. Upon antigen engagement, the TCR signals through associated CD3 subunits, triggering a cascade of intracellular signaling events culminating in T cell activation, proliferation, cytokine secretion, and cytolysis. This makes the TCR alpha-beta chain a key therapeutic target in engineered cellular therapies, especially for cancer and some infectious diseases, but also a contributor to immune-related adverse events and autoimmunity.

Other names

TCR alpha-betaTCRαβAlpha-beta T cell receptorAlpha-beta TCRT cell receptor (TCR)

Redirection of antigen specificity: Engineered TCRs confer novel recognition of tumor or viral antigens, redirecting T cell cytotoxicity. Activation of T cell signaling: Upon antigen (peptide-MHC) binding, TCR-CD3 complex initiates phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs), triggering cascades resulting in T cell activation, proliferation, and effector functions.