AT cell receptor flattens a bulged antigenic peptide presented by a major histocompatibility complex class I molecule

FE Tynan, HH Reid, L Kjer-Nielsen, JJ Miles… - Nature …, 2007 - nature.com
FE Tynan, HH Reid, L Kjer-Nielsen, JJ Miles, MCJ Wilce, L Kostenko, NA Borg
Nature immunology, 2007nature.com
Plasticity of the T cell receptor (TCR) is a hallmark of major histocompatibility complex
(MHC)–restricted T cell recognition. However, it is unclear whether interactions of TCR and
peptide–MHC class I (pMHCI) always conform to this paradigm. Here we describe the
structure of a TCR, ELS4, in its non-ligand-bound form and in complex with a
prominent'bulged'Epstein-Barr virus peptide bound to HLA-B* 3501. This complex was
atypical of previously characterized TCR-pMHCI interactions in that a rigid face of the TCR …
Abstract
Plasticity of the T cell receptor (TCR) is a hallmark of major histocompatibility complex (MHC)–restricted T cell recognition. However, it is unclear whether interactions of TCR and peptide–MHC class I (pMHCI) always conform to this paradigm. Here we describe the structure of a TCR, ELS4, in its non-ligand-bound form and in complex with a prominent 'bulged' Epstein-Barr virus peptide bound to HLA-B*3501. This complex was atypical of previously characterized TCR-pMHCI interactions in that a rigid face of the TCR crumpled the bulged antigenic determinant. This peptide 'bulldozing' created a more featureless pMHCI determinant, allowing the TCR to maximize MHC class I contacts essential for MHC class I restriction of TCR recognition. Our findings represent a mechanism of antigen recognition whereby the plasticity of the T cell response is dictated mainly by adjustments in the MHC-bound peptide.
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