T-cell receptor recognizing H7N9 hemagglutinin-derived peptide–MHC complexes (H7N9 HA-specific TCR)

The T-cell receptor (TCR) recognizing H7N9 hemagglutinin (HA)-derived peptide–MHC complexes is a specialized receptor on the surface of T cells that mediates the recognition of H7N9 influenza virus antigens. These TCRs specifically interact with HA-derived peptides, such as HA336-344 (LYEKVKSQL) and HA518-526 (VLLLWITQV), when presented by Major Histocompatibility Complex (MHC) molecules like HLA-A*02:01. This recognition event is fundamental for the activation of CD8+ cytotoxic T cells, which are responsible for clearing infected cells and providing heterosubtypic immunity. However, some H7N9 HA epitopes have been identified as 'human-like,' potentially leading to T-cell receptor recognition that induces regulatory T cell (Treg) expansion and immune tolerance rather than an effective effector response. This 'viral camouflage' is thought to contribute to the poor immunogenicity and high mortality associated with H7N9 infections. Consequently, these TCR-pMHC interactions are major targets for the design of next-generation vaccines and adoptive T-cell therapies (TCR-T) to overcome immune evasion. Structural characterization of these complexes provides a blueprint for engineering high-affinity TCRs for therapeutic use.

Other names

H7N9 HA-specific T-cell receptorH7-TCR1H7-TCR2TCR recognizing HA336-344/HLA-A*02:01TCR recognizing HA518-526/HLA-A*02:01

Recognition of viral peptides presented by MHC class I, leading to T-cell activation and targeted cell lysis.