SARS-CoV-2 peptide-Human Leukocyte Antigen complex (SARS-CoV-2 pHLA)

The SARS-CoV-2 peptide-Human Leukocyte Antigen (HLA) complex is a molecular assembly formed when viral proteins are processed into short peptides and presented on the cell surface by HLA molecules (1.1.1, 1.1.2). These complexes serve as the essential signal for the adaptive immune system, allowing T-cell receptors (TCRs) to recognize and respond to infected cells (1.1.3, 1.5.1). CD8+ T cells typically recognize peptides presented by HLA Class I molecules, leading to direct lysis of the infected cell, while CD4+ T cells recognize peptides on HLA Class II molecules to coordinate the broader immune response (1.1.4, 1.5.3). In the context of COVID-19, the presentation of immunodominant epitopes from proteins like Spike, Nucleocapsid, and Membrane is critical for viral clearance and long-term immunity (1.2.1, 1.3.2). Therapeutic strategies targeting these complexes include peptide-based vaccines, such as CoVac-1, which aim to induce robust and long-lasting T-cell memory (1.3.1). Additionally, novel modalities like TCR-engineered T-cell (TCR-T) therapies and TCR-mimetic (TCRm) antibodies are being developed to specifically target and eliminate cells presenting these viral antigens (1.4.5). A major challenge in targeting these complexes is the high degree of HLA polymorphism in the human population, which necessitates the development of therapies tailored to specific HLA alleles like HLA-A*02:01 (1.2.2, 1.5.4). Furthermore, the virus may employ immune evasion tactics, such as downregulating HLA expression or mutating key anchor residues in the peptides, to avoid detection (1.5.3, 1.5.5).

Other names

SARS-CoV-2 peptide-MHC complexSARS-CoV-2 pMHCSARS-CoV-2 antigen-HLA complexSARS-CoV-2 immunopeptidomeSARS-CoV-2 antigen-derived peptide-HLA complexes on infected cells

Recognition of the peptide-HLA complex by T-cell receptors (TCRs) or TCR-mimetic antibodies, which triggers an immune response leading to the destruction of the infected cell and the release of antiviral cytokines.