T-cell receptor–MHC complex presenting SARS-CoV-2 nucleocapsid epitopes (TCR-pMHC (SARS-CoV-2 N))

The T-cell receptor–MHC complex presenting SARS-CoV-2 nucleocapsid epitopes is a tripartite molecular assembly essential for the cellular immune response against COVID-19. It consists of a T-cell receptor (TCR) on the surface of a CD8+ or CD4+ T cell, a Major Histocompatibility Complex (MHC) molecule (HLA in humans) on an infected or antigen-presenting cell, and a specific peptide fragment derived from the SARS-CoV-2 nucleocapsid (N) protein. The N protein is highly conserved and immunodominant, making its epitopes, such as N105-113 (SPRWYFYYL) presented by HLA-B*07:02, prime targets for therapeutic intervention. Recognition of this complex triggers T-cell activation, leading to the destruction of virally infected cells and the establishment of long-term immunological memory. This complex is a focal point for the development of adoptive T-cell therapies and next-generation vaccines, particularly for immunocompromised patients who fail to mount adequate antibody responses.

Other names

TCR-pMHC complexTCR-pHLA complexSARS-CoV-2 nucleocapsid peptide-MHC complexHLA-B*07:02-N105-113 complexHLA-A*02:01-N222-230 complexT-cell receptor-peptide-major histocompatibility complex

Recognition of the specific SARS-CoV-2 nucleocapsid peptide-MHC complex by the T-cell receptor (TCR) triggers a signaling cascade that leads to T-cell activation, the release of cytotoxic granules (perforin and granzymes), and the secretion of pro-inflammatory cytokines such as interferon-gamma (IFN-gamma), resulting in the lysis of infected cells.