SARS-CoV-2 membrane protein-derived peptide-MHC complex (SARS-CoV-2 M-pMHC)

The SARS-CoV-2 membrane (M) protein is the most abundant structural protein of the virus and is essential for viral assembly and morphogenesis. During infection, the M protein is processed into short peptide fragments that are presented on the surface of infected cells or professional antigen-presenting cells (APCs) via Major Histocompatibility Complex (MHC) Class I and Class II molecules. These peptide-MHC (pMHC) complexes serve as the primary targets for T-cell recognition, where they are bound by specific T-cell receptors (TCRs) to trigger a cellular immune response. Unlike the Spike protein, the M protein is highly conserved across different SARS-CoV-2 variants, making its MHC-presented epitopes attractive targets for the development of universal vaccines and next-generation T-cell therapies. Therapeutic strategies targeting these epitopes include multi-epitope peptide vaccines (e.g., ISA-106, UB-612) and inactivated whole-virus vaccines (e.g., CoVaxin), which aim to elicit broad and durable T-cell immunity. Such approaches are particularly valuable for providing protection against variants that escape antibody-mediated neutralization and for patients with B-cell deficiencies. However, the effectiveness of these therapies is influenced by host HLA polymorphism and the potential for the virus to evolve mutations that abrogate MHC binding or TCR recognition. Additionally, research into molecular mimicry suggests that certain M protein epitopes may share homology with human lung proteins, necessitating careful screening to avoid autoimmune cross-reactivity.

Other names

SARS-CoV-2 M protein epitopesHLA-restricted SARS-CoV-2 membrane peptidesSARS-CoV-2 M-derived T-cell epitopesSARS-CoV-2 membrane protein antigenic peptides

Induction of T-cell mediated immunity through the recognition of specific viral peptide-MHC complexes by T-cell receptors (TCRs). This interaction activates CD8+ cytotoxic T cells to lyse infected cells and CD4+ helper T cells to coordinate the broader immune response and cytokine release.