SIINFEKL peptide-MHC class I H-2Kb complex (SIINFEKL-H-2Kb)

The SIINFEKL peptide-MHC class I H-2Kb complex is a foundational model system in immunology, consisting of the octapeptide SIINFEKL (residues 257-264) derived from chicken ovalbumin bound to the murine MHC class I molecule H-2Kb (UniProt: P01012). This complex is the primary target for the OT-I T-cell receptor (TCR), a high-affinity transgenic receptor widely used to study the kinetics and requirements of CD8+ T-cell activation and memory formation (PubMed: 8144932). In biological contexts, the complex is generated through the endogenous processing of ovalbumin or via cross-presentation by professional antigen-presenting cells like dendritic cells (PubMed: 10887109). While not a naturally occurring human therapeutic target, the SIINFEKL-H-2Kb system is an essential tool for biotech analysts and researchers to evaluate the efficacy of novel immunotherapies, including cancer vaccines, chimeric antigen receptor (CAR) T-cells, and TCR-like antibodies (PubMed: 9151704). It allows for the precise quantification of antigen-specific immune responses using specialized reagents like MHC tetramers. The system is frequently employed in preclinical oncology to simulate tumor-associated antigens, providing a robust platform for testing the spatial-temporal dynamics of the immunological synapse and the impact of the tumor microenvironment on T-cell function.

Other names

OVA257-264 peptide-H-2Kb complexH-2Kb-SIINFEKLOvalbumin peptide 257-264 presented by H-2KbH2-Kb/SIINFEKL

The complex acts as a specific ligand for the T-cell receptor (TCR) on CD8+ T cells, particularly the OT-I TCR, which triggers the formation of an immunological synapse, downstream phosphorylation cascades (e.g., ZAP-70), and the release of cytotoxic granules (perforin/granzyme) to induce apoptosis in the target cell (PubMed: 8144932).