Invariant Vα19-Jα26 NKT T-cell receptor (Vα19 TCR)

The Invariant Vα19-Jα26 NKT T-cell receptor is a semi-invariant αβ T-cell receptor primarily expressed by a subset of non-conventional T cells in mice, now commonly identified as Mucosal-Associated Invariant T (MAIT) cells (Shimamura et al., 2002). This receptor is characterized by the rearrangement of the Vα19 (TRAV1) and Jα26 (TRAJ33) gene segments, forming an invariant alpha chain that pairs with a limited set of beta chains (Shimamura et al., 2005). Unlike conventional T-cell receptors that recognize peptide antigens on MHC molecules, the Vα19-Jα26 TCR recognizes glycolipid and metabolite antigens presented by the non-polymorphic MHC class I-like molecule, MR1 (Kawachi et al., 2006). Activation of this receptor triggers a rapid and potent immune response, characterized by the secretion of both Th1 and Th2 cytokines, including IFN-γ, IL-4, and IL-17. Due to its role in regulating immune homeostasis and its presence in tissues like the liver and gut, the Vα19-Jα26 TCR is a target for immunotherapeutic strategies. Agonists such as α-mannosylceramide and β-mannosylceramide are being explored for their potential to modulate immune responses in the context of autoimmune diseases, infectious diseases, and cancer (O'Konek et al., 2011). While this specific nomenclature refers to the murine receptor, its human functional homolog is the Vα7.2-Jα33 TCR, which is also restricted by MR1.

Other names

Vα19-Jα33 T-cell receptorVα19i TCRMouse MAIT T-cell receptorTRAV1-TRAJ33 T-cell receptorAV19-AJ33 TCR

Agonist activation of the T-cell receptor complex upon binding to ligands presented by the MR1 molecule.