Invariant natural killer T cell receptor (iNKT TCR) (iNKT TCR)

The invariant natural killer T cell receptor (iNKT TCR) is a specialized semi-invariant αβ T-cell receptor that defines the iNKT cell lineage (NIH, 2018). In humans, it is characterized by a conserved Vα24-Jα18 α-chain paired with a Vβ11 β-chain, which allows for the specific recognition of glycolipid antigens presented by the MHC class I-like molecule CD1d (NIH, 2016). Unlike conventional T-cell receptors that recognize peptides, the iNKT TCR recognizes lipids like alpha-galactosylceramide (α-GalCer), enabling iNKT cells to act as a bridge between innate and adaptive immunity (Caltag Medsystems, 2024). Upon activation, the receptor triggers a rapid and massive release of cytokines, including IFN-γ and IL-4, which can orchestrate a broad range of immune responses (NIH, 2020). The iNKT TCR is a significant therapeutic target in oncology, as its activation can stimulate potent anti-tumor immunity and recruit other effector cells like NK and CD8+ T cells (NIH, 2024). Synthetic agonists such as KRN7000 and ABX196 have been developed to harness this pathway for treating various cancers and infectious diseases (Patsnap, 2025). However, therapeutic application is complicated by the potential for iNKT cell anergy—a state of long-term unresponsiveness following initial stimulation—and the risk of systemic cytokine release syndrome (NIH, 2020). Ongoing research explores the use of biased agonists, monoclonal antibodies, and CAR-iNKT cell therapies to optimize the clinical utility of targeting this receptor (Science Immunology, 2022).

Other names

Vα24-Jα18 TCRVα14-Jα18 TCRType I NKT cell receptorCD1d-restricted T-cell receptorSemi-invariant T-cell receptor

Agonist activation of iNKT cells through the formation of a ternary complex between the TCR, CD1d, and a glycolipid ligand, leading to rapid cytokine release and immune modulation (NIH, 2024).