Ovalbumin-specific T-cell receptor (OT-I TCR) (OT-I TCR)

The Ovalbumin-specific T-cell receptor (OT-I TCR) is a transgenic heterodimeric protein composed of alpha and beta chains that specifically recognizes the SIINFEKL peptide (residues 257–264 of chicken ovalbumin) presented by the murine MHC class I molecule H-2Kb (Hogquist et al., 1994, Cell). This receptor serves as a primary model system in immunology for investigating the activation, differentiation, and effector functions of CD8+ cytotoxic T lymphocytes (The Jackson Laboratory, 2024). In therapeutic research, the OT-I TCR is utilized to evaluate the efficacy of adoptive cell transfer (ACT) therapies and to study the dynamics of the immunological synapse (PubMed: 31515463). The interaction between the TCR and the SIINFEKL-MHC complex initiates a signaling cascade through the CD3 complex, involving phosphorylation of ITAMs and activation of downstream pathways like MAPK and NF-kappaB (UniProt: P01850). This activation leads to the secretion of cytotoxic granules (perforin and granzymes) and pro-inflammatory cytokines such as IFN-gamma and TNF-alpha (PubMed: 25108026). While the OT-I TCR itself is a murine research tool, it provides critical insights into the development of human TCR-engineered T-cell (TCR-T) therapies for oncology and infectious diseases (PubMed: 28257305). Therapeutic challenges associated with targeting such receptors include potential off-target reactivity and the risk of cytokine release syndrome in clinical applications (PubMed: 30206131).

Other names

SIINFEKL-specific T-cell receptorOT-1 TCRH-2Kb/SIINFEKL TCROvalbumin-specific T-cell receptor IC57BL/6-Tg(TcraTcrb)1100Mjb/J TCR

The OT-I TCR specifically recognizes the SIINFEKL peptide presented by the murine MHC class I molecule H-2Kb, triggering a signaling cascade through the CD3 complex that leads to T-cell proliferation, cytokine release, and target cell lysis.