Structural features underlying T-cell receptor sensitivity to concealed MHC class I micropolymorphisms

摘要

The initiation of a killer (cyto-toxic) immune response depends on the ability of αβ T-cell receptors (αβTCR) expressed on CD8~+ T lymphocytes to recognize their ligand, namely MHC class I proteins bound to fragments of pathogens at the surface of infected cells. MHC class I proteins capture these short segments of pathogens (known as "peptides" or "epitopes") in-tracellularly, and through a complex sequence of events the resulting MHC class I-peptide complexes are transported to the cell surface where they are recognized by CD8~+ T cells that express specific αβTCR pairs. Engagement of MHC class I-peptide by apTCR results in a signaling cascade leading to T-cell activation resulting in the elimination of infected cells.