8TRL image
Deposition Date 2023-08-09
Release Date 2024-07-31
Last Version Date 2024-11-13
Entry Detail
PDB ID:
8TRL
Keywords:
Title:
T cell recognition of citrullinated alpha-enolase peptide presented by HLA-DR4
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.40 Å
R-Value Free:
0.23
R-Value Work:
0.20
R-Value Observed:
0.21
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:HLA class II histocompatibility antigen, DR alpha chain
Gene (Uniprot):HLA-DRA
Chain IDs:A, F (auth: D)
Chain Length:181
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:HLA class II histocompatibility antigen, DRB1 beta chain
Gene (Uniprot):HLA-DRB1
Chain IDs:B, G (auth: E)
Chain Length:190
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Alpha-enolase
Chain IDs:C, H (auth: F)
Chain Length:13
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:RA2.7 TCR alpha chain
Chain IDs:D (auth: I), I (auth: G)
Chain Length:204
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:RA2.7 TCR beta chain
Chain IDs:E (auth: J), J (auth: H)
Chain Length:245
Number of Molecules:2
Biological Source:Homo sapiens
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
CIR C ARG modified residue
Primary Citation
The molecular basis underlying T cell specificity towards citrullinated epitopes presented by HLA-DR4.
Nat Commun 15 6201 6201 (2024)
PMID: 39043656 DOI: 10.1038/s41467-024-50511-w

Abstact

CD4+ T cells recognising citrullinated self-epitopes presented by HLA-DRB1 bearing the shared susceptibility epitope (SE) are implicated in rheumatoid arthritis (RA). However, the underlying T cell receptor (TCR) determinants of epitope specificity towards distinct citrullinated peptide antigens, including vimentin-64cit59-71 and α-enolase-15cit10-22 remain unclear. Using HLA-DR4-tetramers, we examine the T cell repertoire in HLA-DR4 transgenic mice and observe biased TRAV6 TCR gene usage across these two citrullinated epitopes which matches with TCR bias previously observed towards the fibrinogen β-74cit69-81 epitope. Moreover, shared TRAV26-1 gene usage is evident in four α-enolase-15cit10-22 reactive T cells in three human samples. Crystal structures of mouse TRAV6+ and human TRAV26-1+ TCR-HLA-DR4 complexes presenting vimentin-64cit59-71 and α-enolase-15cit10-22, respectively, show three-way interactions between the TCR, SE, citrulline, and the basis for the biased selection of TRAV genes. Position 2 of the citrullinated epitope is a key determinant underpinning TCR specificity. Accordingly, we provide a molecular basis of TCR specificity towards citrullinated epitopes.

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Primary Citation of related structures