Ovalbumin-specific CD8+ T-cell receptor (recognizing SIINFEKL-H-2Kb) (OT-I TCR)

The Ovalbumin-specific CD8+ T-cell receptor (OT-I TCR) is a well-characterized heterodimeric receptor that specifically recognizes the SIINFEKL peptide (residues 257-264 of chicken ovalbumin) when presented by the murine MHC class I molecule H-2Kb (Hogquist et al., 1994, Cell). It serves as a gold-standard model in immunology for studying CD8+ T-cell biology, including development, activation, and effector functions (Curtsinger et al., 1999, J Immunol). In research, the OT-I TCR is frequently utilized in transgenic mouse models to evaluate the efficacy of vaccines, cancer immunotherapies, and the mechanisms of T-cell exhaustion (Zehn et al., 2009, Nature). The interaction between the TCR and the SIINFEKL-H-2Kb complex triggers intracellular signaling via the CD3 complex, leading to the secretion of pro-inflammatory cytokines like IFN-gamma and the release of cytotoxic granules (Rosette et al., 2001, Immunity). While primarily an experimental tool, it provides critical insights into the design of TCR-engineered T-cell therapies for human diseases. Its high affinity and specificity make it an ideal system for testing novel drug delivery systems and antigen-presentation platforms. The receptor is composed of Vα2 and Vβ5 chains, which define its unique specificity (UniProt). It is often used in adoptive cell transfer experiments to track the fate of antigen-specific T cells in vivo. This system has been instrumental in defining the requirements for T-cell activation and tolerance.

Other names

OT-I T-cell receptorSIINFEKL-specific TCROVA257-264-specific TCRVα2Vβ5 T-cell receptorOvalbumin-specific CD8+ T-cell receptor

The OT-I TCR recognizes the SIINFEKL peptide presented by the H-2Kb MHC class I molecule, initiating a signaling cascade through the CD3 complex that leads to T-cell activation, proliferation, and the production of cytotoxic molecules like perforin and granzymes (Rosette et al., 2001, Immunity).