PMID: 15849183 , Related PDB ids: 1ZHK, 1ZHL

Authors:

Tynan FE, Borg NA, Miles JJ, Beddoe T, El-Hassen D, Silins SL, van Zuylen WJ, Purcell AW, Kjer-Nielsen L, McCluskey J, Burrows SR, Rossjohn J

Title:

High resolution structures of highly bulged viral epitopes bound to major histocompatibility complex class I. Implications for T-cell receptor engagement and T-cell immunodominance.

Journal:

J Biol Chem. 2005 Jun 24;280(25):23900-9. Epub 2005 Apr 22.

Abstract:

Although HLA class I alleles can bind epitopes up to 14 amino acids in length, little is known about the immunogenicity or the responding T-cell repertoire against such determinants. Here, we describe an HLA-B*3508-restricted cytotoxic T lymphocyte response to a 13-mer viral epitope (LPEPLPQGQLTAY). The rigid, centrally bulged epitope generated a biased T-cell response. Only the N-terminal face of the peptide bulge was critical for recognition by the dominant clonotype SB27. The SB27 public T-cell receptor (TcR) associated slowly onto the complex between the bulged peptide and the major histocompatibility complex, suggesting significant remodeling upon engagement. The broad antigen-binding cleft of HLA-B*3508 represents a critical feature for engagement of the public TcR, as the narrower binding cleft of HLA-B*3501(LPEPLPQGQLTAY), which differs from HLA-B*3508 by a single amino acid polymorphism (Arg156 --> Leu), interacted poorly with the dominant TcR. Biased TcR usage in this cytotoxic T lymphocyte response appears to reflect a dominant role of the prominent peptide x major histocompatibility complex class I surface.