Ovalbumin-derived peptide-Major Histocompatibility Complex complex (OVA-pMHC)

The Ovalbumin-derived peptide bound to the Major Histocompatibility Complex (MHC) is a fundamental model system used in immunology to study antigen presentation and T-cell activation (NIH, 2023). This complex typically involves specific epitopes from chicken egg white albumin, such as the MHC Class I-restricted octapeptide SIINFEKL (OVA 257-264) or the MHC Class II-restricted peptide OVA 323-339, non-covalently bound to the peptide-binding groove of MHC molecules like H-2Kb or I-Ad (Buus S et al., PNAS, 1986). Recognition of these complexes by specific T-cell receptors (TCRs), such as those on OT-I (CD8+) and OT-II (CD4+) transgenic T cells, triggers robust adaptive immune responses, including cytokine production and cytotoxic activity (Creative Diagnostics, 2024). While not a natural human therapeutic target, the OVA-pMHC system is an essential tool for evaluating the efficacy of vaccines, adjuvants, and adoptive cell therapies in preclinical research. It serves as a surrogate for tumor-associated antigens or viral epitopes, allowing researchers to quantify the kinetics of antigen processing and the magnitude of the resulting T-cell response (Porgador A et al., Immunity, 1997). Reagents like the 25-D1.1 monoclonal antibody, which specifically recognizes the SIINFEKL-H-2Kb complex, enable precise monitoring of antigen-presenting cell (APC) function and the development of novel immunotherapeutic strategies (Cytek Biosciences, 2024).

Other names

SIINFEKL-H-2Kb complexOVA 257-264-MHC complexOVA 323-339-MHC complexOvalbumin-MHC complexpMHC complex (Ovalbumin)

Presentation of antigenic peptide to T-cell receptors (TCRs) to initiate adaptive immune responses.