T-cell receptor recognizing influenza hemagglutinin-derived peptides in MHC class II (HA-specific TCR)

The T-cell receptor (TCR) recognizing influenza hemagglutinin (HA)-derived peptides in the context of MHC class II is a fundamental mediator of the adaptive immune response to influenza infection (Source: PubMed, PMID: 11916393). These TCRs are typically expressed on CD4+ T helper cells and are specialized to recognize conserved viral epitopes, most notably the HA 306-318 peptide, when presented by MHC class II molecules such as HLA-DRB1*04:01 (Source: PDB, 1FYT). This recognition event is a prerequisite for T-cell activation, leading to the secretion of cytokines like interferon-gamma and the provision of help to B cells for high-affinity antibody production (Source: Janeway's Immunobiology). In clinical research, these TCRs serve as templates for TCR-engineered T-cell (TCR-T) therapies and are central to the design of "universal" influenza vaccines that target stable regions of the virus (Source: NIH, National Institute of Allergy and Infectious Diseases). However, therapeutic application faces challenges including MHC restriction, which limits efficacy to specific HLA-typed populations, and the risk of cytokine release syndrome or off-target cross-reactivity (Source: Frontiers in Immunology).

Other names

Influenza HA-specific TCRHA-reactive CD4+ TCRHemagglutinin-specific T-cell receptorHA306-318-specific TCRTCR-HAHA1.7 TCR

The TCR complex recognizes the influenza hemagglutinin peptide (specifically the conserved HA 306-318 epitope) presented by MHC class II molecules (such as HLA-DR4), triggering a signaling cascade through the CD3 complex and ZAP-70 that leads to T-cell proliferation and the secretion of pro-inflammatory cytokines like IFN-gamma and IL-2 (Source: PubMed, PMID: 11916393).