Clone REA871 recognizes the human variable β 7.1 subunit of the αβ T cell receptor (TCR Vβ7.1). 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 Vβ7.1 is a variant of the TCR β chain. αβ T cells express a diverse αβ 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 the 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 αβ T cell–mediated immunity and underpins MHC restriction.

Additional information: Clone REA871 displays negligible binding to Fc receptors.