Ovalbumin peptide-Major Histocompatibility Complex class II complex (OVA-MHCII)

The Ovalbumin peptide-Major Histocompatibility Complex class II complex (OVA-MHCII) is a specialized antigen-MHC complex that serves as the therapeutic target for ovalbumin-specific Type 1 regulatory T cell (Tr1) therapies (Desreumaux et al., 2012, Gastroenterology). This complex consists of a peptide fragment derived from the egg white protein ovalbumin, typically the OVA 323-339 epitope, presented by Major Histocompatibility Complex (MHC) class II molecules on the surface of antigen-presenting cells (Roncarolo et al., 2006, Immunological Reviews). In clinical applications such as Ovasave (TX-RAD), autologous Tr1 cells are isolated or engineered to recognize this specific complex via their T-cell receptors (TCRs) (Sangamo Therapeutics, 2024). Upon binding to the OVA-MHCII complex, the Tr1 cells are activated to secrete high levels of immunosuppressive cytokines, primarily interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta), which facilitate localized immune tolerance and suppress pathogenic inflammatory responses (Gagliani et al., 2015, European Journal of Immunology). This therapeutic strategy is primarily investigated for inflammatory bowel diseases, such as Crohn's disease, where oral administration of ovalbumin is used to induce the presentation of the target complex in the gut mucosa, thereby directing the anti-inflammatory activity of the Tr1 cells to the site of disease (Bacchetta et al., 2014, Frontiers in Immunology).

Other names

OVA323-339-MHCIIOvalbumin-MHC II complexOVA-HLA-DR complexOvalbumin peptide-HLA class II complexOVA-specific Tr1 target

Activation of Tr1 cells via TCR-mediated recognition of the OVA-MHCII complex, triggering the release of IL-10 and TGF-beta to induce localized immune suppression and bystander tolerance.