SARS-CoV-2 ORF3a protein-derived peptides presented by HLA class I (SARS-CoV-2 ORF3a-HLA-I) (SARS-CoV-2 ORF3a-HLA-I)

SARS-CoV-2 ORF3a protein-derived peptides presented by HLA class I are molecular complexes formed when fragments of the viral accessory protein ORF3a are displayed on the cell surface by Human Leukocyte Antigen (HLA) class I molecules. The ORF3a protein itself functions as a viroporin, forming ion channels that promote viral release and trigger inflammatory responses, including the NLRP3 inflammasome (UniProt P0DTC3). These peptide-HLA (pHLA) complexes serve as the primary signal for CD8+ cytotoxic T cells to identify and destroy SARS-CoV-2 infected cells (PubMed: 32887270). Therapeutic strategies targeting these complexes include TCR-engineered T cells (TCR-T) and peptide-based vaccines designed to elicit a robust cellular immune response (PubMed: 33909487). Such approaches are particularly valuable for providing long-term immunity and protection against variants that may evade antibody-mediated neutralization. However, the high degree of HLA polymorphism in the human population means that specific peptide targets are often restricted to certain HLA alleles, such as HLA-A*02:01 (PubMed: 34161331).

Other names

SARS-CoV-2 ORF3a-MHC I complexORF3a epitope-HLA complexSARS-CoV-2 accessory protein 3a-HLA-I

T-cell receptor-mediated recognition of the peptide-HLA complex leading to cytotoxic T-lymphocyte activation and lysis of infected cells.