4Y1A | pdb_00004y1a

T cell receptor reversed polarity recognition of a self-antigen major histocompatibility complex.

Beringer, D.X.,&nbspKleijwegt, F.S.,&nbspWiede, F.,&nbspvan der Slik, A.R.,&nbspLoh, K.L.,&nbspPetersen, J.,&nbspDudek, N.L.,&nbspDuinkerken, G.,&nbspLaban, S.,&nbspJoosten, A.,&nbspVivian, J.P.,&nbspChen, Z.,&nbspUldrich, A.P.,&nbspGodfrey, D.I.,&nbspMcCluskey, J.,&nbspPrice, D.A.,&nbspRadford, K.J.,&nbspPurcell, A.W.,&nbspNikolic, T.,&nbspReid, H.H.,&nbspTiganis, T.,&nbspRoep, B.O.,&nbspRossjohn, J.

(2015) Nat Immunol&nbsp16: 1153-1161

• PubMed:&nbsp26437244&nbspSearch on PubMed
• DOI:&nbsphttps://doi.org/10.1038/ni.3271
• Primary Citation of Related Structures: &nbsp
  4Y19, 4Y1A


• PubMed Abstract:&nbsp
  

  Central to adaptive immunity is the interaction between the αβ T cell receptor (TCR) and peptide presented by the major histocompatibility complex (MHC) molecule. Presumably reflecting TCR-MHC bias and T cell signaling constraints, the TCR universally adopts a canonical polarity atop the MHC. We report the structures of two TCRs, derived from human induced T regulatory (iT(reg)) cells, complexed to an MHC class II molecule presenting a proinsulin-derived peptide. The ternary complexes revealed a 180° polarity reversal compared to all other TCR-peptide-MHC complex structures. Namely, the iT(reg) TCR α-chain and β-chain are overlaid with the α-chain and β-chain of MHC class II, respectively. Nevertheless, this TCR interaction elicited a peptide-reactive, MHC-restricted T cell signal. Thus TCRs are not 'hardwired' to interact with MHC molecules in a stereotypic manner to elicit a T cell signal, a finding that fundamentally challenges our understanding of TCR recognition.

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Organizational Affiliation:&nbsp

Infection and Immunity Program and The Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.