Influenza Hemagglutinin-specific CD8+ T-cell receptor (HA-specific TCR)

CD8+ T-cell receptors (TCRs) recognizing hemagglutinin (HA)-derived peptides are specialized immune receptors that play a pivotal role in the cellular defense against influenza viruses. These TCRs specifically identify short peptide fragments of the HA protein, such as the immunodominant HA 210-219 epitope, when they are presented by Major Histocompatibility Complex (MHC) class I molecules like HLA-A*02:01 [1][2]. Upon recognition of the peptide-MHC complex, the TCR initiates a signaling cascade that activates the CD8+ T cell, resulting in the targeted destruction of virus-infected cells through the release of cytotoxins and cytokines [3]. While antibodies primarily target the surface of the virus to prevent entry, these TCRs provide a critical second line of defense by eliminating cells that have already been infected, often showing higher cross-reactivity across different viral strains [4]. In the context of drug development, these receptors are primary targets for TCR-engineered T-cell (TCR-T) therapies and the design of next-generation universal influenza vaccines [5]. Monitoring the activity and frequency of these TCRs using peptide-MHC tetramers is a standard approach for assessing vaccine efficacy and the depth of the cellular immune response [6].

Other names

Hemagglutinin-specific T-cell receptorHA-specific CD8+ TCRInfluenza HA-reactive TCRCD8+ TCR recognizing HA/MHC-I

The receptor binds specifically to influenza hemagglutinin (HA) peptides presented by MHC class I molecules on the surface of infected cells. This binding event, stabilized by the CD8 co-receptor, triggers the TCR-CD3 signaling complex, leading to the activation of the T cell, release of cytotoxic granules (perforin/granzymes), and secretion of pro-inflammatory cytokines to eliminate the viral reservoir.