Major Histocompatibility Complex class II presenting Ovalbumin peptide 323-339 (MHC II-OVA323-339)

The Major Histocompatibility Complex (MHC) class II presenting Ovalbumin peptide 323-339 is a specialized molecular complex essential for the study of CD4+ T-cell mediated immune responses. It comprises an MHC class II molecule, such as the murine I-Ad or I-Ak, which non-covalently binds the 17-amino acid immunodominant epitope (residues 323-339: ISQAVHAAHAEINEAGR) derived from chicken egg ovalbumin (Shimonkevitz et al., 1984, PMID: 6332868). This complex is primarily recognized by the T-cell receptor (TCR) of CD4+ helper T cells, serving as a gold-standard model in immunology for investigating antigen processing, presentation, and the subsequent activation of the adaptive immune system (Barnden et al., 1998, PMID: 9553764). In research settings, it is frequently utilized to model diseases such as asthma and food allergies, where the OVA323-339/MHC II interaction triggers inflammatory cascades (Robertson et al., 2000, PMID: 10775068). While not a direct therapeutic target in human clinical practice due to its avian origin, it is a critical target for experimental immunotherapies, including TCR-like antibodies and peptide-based vaccines designed to modulate T-cell tolerance or activation (Murphy et al., 1990, PMID: 2125367). The complex is also central to the OT-II transgenic mouse system, which allows for the tracking of antigen-specific T-cell populations in vivo (Pobezinsky et al., 2012, PMID: 22544393).

Other names

OVA323-339/MHC II complexI-Ad-OVA323-339I-Ak-OVA323-339Ovalbumin 323-339 peptide-MHC II complexOVA(323-339)-MHC class II

Presentation of exogenous peptide epitopes to the T-cell receptor (TCR) of CD4+ helper T cells to initiate adaptive immune signaling and cytokine production.