Hemagglutinin peptide-MHC class I complex (HA-MHC I)

The Hemagglutinin peptide-MHC class I complex is a molecular assembly consisting of a proteolytically processed fragment of the influenza virus hemagglutinin (HA) protein non-covalently bound to a human leukocyte antigen (HLA) class I molecule. This complex is expressed on the surface of antigen-presenting cells (APCs) and infected host cells, where it serves as a specific recognition element for the adaptive immune system (Janeway et al., 2001, Immunobiology). The primary biological role of this complex is to present viral antigens to the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes (CTLs). Upon recognition, the CTLs are activated to release cytotoxic granules, such as perforin and granzymes, leading to the targeted apoptosis of the infected cell (PubMed: 15140910). In the pharmaceutical industry, this complex is a high-priority target for the design of universal influenza vaccines and T-cell-based immunotherapies. By targeting conserved HA epitopes presented by MHC class I, researchers aim to develop therapies that provide broad-spectrum protection against multiple influenza strains, bypassing the limitations of traditional antibody-mediated seasonal vaccines (Nature Biotechnology, 2013).

Other names

HA-HLA class I complexInfluenza hemagglutinin peptide-HLA complexpMHC complex (Hemagglutinin)HA-derived peptide-MHC I

Presentation of viral epitopes to CD8+ T cells to trigger cellular immunity and apoptosis of infected cells.