Human T-cell receptor (TCR) (TCR)

The Human T-cell receptor (TCR) is a membrane-bound heterodimeric protein found on the surface of T lymphocytes, responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules. In the context of influenza, TCRs on CD8+ and CD4+ T cells target conserved internal proteins such as nucleoprotein (NP), matrix protein 1 (M1), and the stalk domain of hemagglutinin (HA), which are less prone to the rapid antigenic drift seen in the HA globular head. Recognition of these conserved epitopes allows for heterosubtypic immunity, providing protection against multiple strains and subtypes of influenza A virus, including seasonal and potentially pandemic strains. Therapeutic strategies targeting these TCRs include universal influenza vaccines (UIVs) designed to expand the repertoire of cross-reactive T cells and adoptive TCR-T cell therapies that use engineered T cells to directly target infected cells. The interaction between the TCR and the peptide-MHC complex triggers a signaling cascade that leads to T-cell activation, cytokine production (e.g., IFN-gamma, TNF-alpha), and the destruction of virus-infected cells.

Other names

T-cell antigen receptorαβ T-cell receptorCD3-TCR complexInfluenza-specific T-cell receptorConserved influenza epitope-specific T-cell receptor

TCR-pMHC interaction triggers T-cell activation, leading to the release of cytotoxic granules (perforin, granzymes) and cytokines (IFN-gamma, TNF-alpha) to kill infected cells; vaccines induce expansion and memory of these specific T-cell populations.