SIINFEKL ovalbumin-derived peptide presented by MHC class I H-2K^b (SIINFEKL-H-2K^b)

The SIINFEKL-H-2K^b complex is a well-characterized model antigen system consisting of the ovalbumin-derived peptide SIINFEKL (residues 257–264) bound to the murine MHC class I molecule H-2K^b (Rotzschke et al., 1991, Nature). This complex is primarily used in immunological research to study the mechanisms of antigen processing, presentation, and the activation of CD8+ T cells. In the C57BL/6 mouse model, the OT-I transgenic T cell line specifically recognizes this complex, making it a gold standard for evaluating T cell-mediated immune responses (Hogquist et al., 1994, Cell). While not a direct human therapeutic target, it serves as a critical tool for developing and testing immunotherapies, such as TCR-engineered T cells and cancer vaccines. The complex is often targeted by specialized monoclonal antibodies, like 25-D1.1, which recognize the specific peptide-MHC conformation (Porgador et al., 1997, Immunity). Its study has provided foundational insights into how the immune system identifies and eliminates infected or malignant cells.

Other names

OVA257-264H-2K^b-SIINFEKLOvalbumin peptide 257-264SIINFEKL-MHC class I complex

The complex acts as a ligand for specific T-cell receptors (TCRs), such as the OT-I TCR, triggering a signaling cascade that leads to the activation and proliferation of CD8+ T cells and subsequent lysis of the target cell (Hogquist et al., 1994, Cell).