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

The OT-I T-cell receptor (TCR) is a highly specific murine receptor that recognizes the ovalbumin-derived octapeptide SIINFEKL (residues 257-264) in the context of the H-2Kb major histocompatibility complex (MHC) class I molecule (Hogquist et al., 1994, Cell). It is the defining feature of the OT-I transgenic mouse model, where the majority of CD8+ T cells express this specific TCR, making it an indispensable tool in cellular immunology (The Jackson Laboratory, Stock No: 003831). The receptor is a heterodimer consisting of Valpha2 and Vbeta5 chains. In research, it is used to investigate the dynamics of T-cell priming, memory formation, and the efficacy of various immunotherapy strategies, including TCR-engineered T-cell (TCR-T) therapies (PubMed, PMID: 25108027). While primarily a research tool, the principles derived from OT-I TCR studies directly inform the design of human therapeutic TCRs for cancer treatment. Its interaction with the peptide-MHC complex serves as a gold standard for measuring TCR affinity and signaling thresholds.

Other names

Ovalbumin-specific T-cell receptorSIINFEKL-specific T-cell receptorOT-1 TCRValpha2/Vbeta5 T-cell receptor

The OT-I TCR recognizes the SIINFEKL peptide presented by the H-2Kb MHC class I molecule, triggering a signaling cascade through the CD3 complex that leads to T-cell proliferation, cytokine production, and targeted lysis of antigen-presenting cells (PubMed, PMID: 8124823).