Norovirus peptide–Human Leukocyte Antigen complex (Norovirus pHLA complex)

The Norovirus peptide–Human Leukocyte Antigen (pHLA) complex is a molecular assembly consisting of a norovirus-derived peptide fragment bound within the groove of a Human Leukocyte Antigen (HLA) molecule on the surface of a host cell [1]. These complexes are formed when norovirus proteins, such as the major capsid protein (VP1) or non-structural proteins (e.g., NS6 protease), are processed by the proteasome and loaded onto HLA Class I or Class II molecules [2]. Once expressed on the cell surface of infected intestinal epithelial cells or professional antigen-presenting cells (APCs), they serve as the specific target for T-cell receptors (TCRs) on CD8+ cytotoxic T cells and CD4+ helper T cells [3]. This interaction is fundamental to the adaptive immune response against norovirus, leading to the destruction of infected cells and the secretion of antiviral cytokines like IFN-gamma [1]. In therapeutic development, these pHLA complexes are targeted by epitope-based vaccines and are being explored as targets for TCR-engineered T-cell therapies, particularly for treating chronic norovirus in immunocompromised individuals [4]. The high degree of HLA polymorphism and the rapid evolution of norovirus strains present significant challenges, as mutations in the viral peptide can lead to immune escape by preventing HLA binding or TCR recognition [5]. [1] Malm et al. (2014) J Gen Virol; [2] Lindesmith et al. (2010) Vaccine; [3] Tomaras et al. (2013) Clin Vaccine Immunol; [4] HilleVax (2023) Pipeline Data; [5] Parra (2019) Viruses.

Other names

Norovirus antigen–HLA complexNorovirus pMHCNorovirus epitope–HLA complexNorovirus peptide–MHC class I complexNorovirus antigen–MHC complex

T-cell receptor (TCR) mediated recognition of viral peptides presented on HLA molecules, leading to cytotoxic T-lymphocyte (CTL) activation and lysis of infected cells.