SARS-CoV-2 Spike protein peptide-MHC complex (Spike-pMHC)

The SARS-CoV-2 Spike protein peptide-MHC complex is a molecular assembly formed when the viral Spike protein is proteolytically processed into short peptides and loaded onto Major Histocompatibility Complex (MHC) Class I or Class II molecules for display on the cell surface. MHC Class I molecules present these peptides to CD8+ cytotoxic T cells, while MHC Class II molecules, primarily on professional antigen-presenting cells (APCs), present them to CD4+ helper T cells (Sette & Crotty, 2021). This presentation is the essential trigger for the adaptive immune system to recognize SARS-CoV-2 and initiate a targeted cellular response. COVID-19 vaccines, such as mRNA and viral vector platforms, function by inducing host cells to produce the Spike protein, which is subsequently presented as pMHC complexes to prime T-cell memory (Sahin et al., 2020). The specific repertoire of peptides presented is highly dependent on an individual's HLA genotype, which influences the breadth and magnitude of the immune response (Grifoni et al., 2020). Research into these complexes is vital for developing T-cell-based therapies and ensuring vaccine efficacy against emerging viral variants that may harbor mutations within these critical epitopes (Altmann & Boyton, 2020). These complexes are also the target of diagnostic tools like MHC-peptide multimers used to quantify antigen-specific T-cell populations.

Other names

Spike-HLA complexSARS-CoV-2 S-peptide-MHCSpike antigen-MHC complexpMHC complexSARS-CoV-2 Spike peptide-HLA complex

Induction of T-cell mediated immunity through T-cell receptor (TCR) recognition of the peptide-MHC complex.