Clone REA654 recognizes the human variable β2 subunit of the α/β T cell receptor (TCR Vβ2). The TCR is a heterodimeric glycoprotein associated with the CD3 antigen. The α and β TCR chains are composed of constant and variable regions, each encoded by distinct gene segments. TCR Vβ2 is a variant of the TCR β chain. α/β T cells express a diverse α/β TCR repertoire that specifically co-recognizes self or foreign antigen bound to antigen-presenting molecules, which thereby leads to T cell–mediated immunity. For example, the TCR can directly bind to peptide fragments, riboflavin precursors, and lipid antigens that are presented by major histocompatibility complex (MHC) molecules, MR1 and CD1, respectively. In each case, the antigen sits within the antigen-binding cleft, whereupon the TCR recognizes a composite surface formed by the antigen-presenting molecule and surface-exposed regions of the antigen itself. This co-recognition paradigm is a central tenet of α/β T cell–mediated immunity and underpins MHC restriction.

Additional information: Clone REA654 displays negligible binding to Fc receptors.