4z7u: Difference between revisions
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''' | ==S13 complex== | ||
<StructureSection load='4z7u' size='340' side='right' caption='[[4z7u]], [[Resolution|resolution]] 2.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4z7u]] is a 10 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4Z7U OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4Z7U FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=FUC:ALPHA-L-FUCOSE'>FUC</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4z7v|4z7v]], [[4z7w|4z7w]]</td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4z7u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4z7u OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4z7u RCSB], [http://www.ebi.ac.uk/pdbsum/4z7u PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
In HLA-DQ8-associated celiac disease (CD), the pathogenic T cell response is directed toward an immunodominant alpha-gliadin-derived peptide (DQ8-glia-alpha1). However, our knowledge of TCR gene usage within the primary intestinal tissue of HLA-DQ8+ CD patients is limited. We identified two populations of HLA-DQ8-glia-alpha1 tetramer+ CD4+ T cells that were essentially undetectable in biopsy samples from patients on a gluten-free diet but expanded rapidly and specifically after antigenic stimulation. Distinguished by expression of TRBV9, both T cell populations displayed biased clonotypic repertoires and reacted similarly against HLA-DQ8-glia-alpha1. In particular, TRBV9 paired most often with TRAV26-2, whereas the majority of TRBV9- TCRs used TRBV6-1 with no clear TRAV gene preference. Strikingly, both tetramer+/TRBV9+ and tetramer+/TRBV9- T cells possessed a non-germline-encoded arginine residue in their CDR3alpha and CDR3beta loops, respectively. Comparison of the crystal structures of three TRBV9+ TCRs and a TRBV9- TCR revealed that, as a result of distinct TCR docking modes, the HLA-DQ8-glia-alpha1 contacts mediated by the CDR3-encoded arginine were almost identical between TRBV9+ and TRBV9- TCRs. In all cases, this interaction centered on two hydrogen bonds with a specific serine residue in the bound peptide. Replacement of serine with alanine at this position abrogated TRBV9+ and TRBV9- clonal T cell proliferation in response to HLA-DQ8-glia-alpha1. Gluten-specific memory CD4+ T cells with structurally and functionally conserved TCRs therefore predominate in the disease-affected tissue of patients with HLA-DQ8-mediated CD. | |||
Determinants of Gliadin-Specific T Cell Selection in Celiac Disease.,Petersen J, van Bergen J, Loh KL, Kooy-Winkelaar Y, Beringer DX, Thompson A, Bakker SF, Mulder CJ, Ladell K, McLaren JE, Price DA, Rossjohn J, Reid HH, Koning F J Immunol. 2015 May 6. pii: 1500161. PMID:25948817<ref>PMID:25948817</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
[[Category: | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Koning, F]] | |||
[[Category: Petersen, J]] | |||
[[Category: Reid, H H]] | |||
[[Category: Rossjohn, J]] | [[Category: Rossjohn, J]] | ||
[[Category: | [[Category: Immune receptor-ligand complex]] | ||
[[Category: | [[Category: Immune system]] | ||
Revision as of 15:39, 3 June 2015
S13 complexS13 complex
Structural highlights
Publication Abstract from PubMedIn HLA-DQ8-associated celiac disease (CD), the pathogenic T cell response is directed toward an immunodominant alpha-gliadin-derived peptide (DQ8-glia-alpha1). However, our knowledge of TCR gene usage within the primary intestinal tissue of HLA-DQ8+ CD patients is limited. We identified two populations of HLA-DQ8-glia-alpha1 tetramer+ CD4+ T cells that were essentially undetectable in biopsy samples from patients on a gluten-free diet but expanded rapidly and specifically after antigenic stimulation. Distinguished by expression of TRBV9, both T cell populations displayed biased clonotypic repertoires and reacted similarly against HLA-DQ8-glia-alpha1. In particular, TRBV9 paired most often with TRAV26-2, whereas the majority of TRBV9- TCRs used TRBV6-1 with no clear TRAV gene preference. Strikingly, both tetramer+/TRBV9+ and tetramer+/TRBV9- T cells possessed a non-germline-encoded arginine residue in their CDR3alpha and CDR3beta loops, respectively. Comparison of the crystal structures of three TRBV9+ TCRs and a TRBV9- TCR revealed that, as a result of distinct TCR docking modes, the HLA-DQ8-glia-alpha1 contacts mediated by the CDR3-encoded arginine were almost identical between TRBV9+ and TRBV9- TCRs. In all cases, this interaction centered on two hydrogen bonds with a specific serine residue in the bound peptide. Replacement of serine with alanine at this position abrogated TRBV9+ and TRBV9- clonal T cell proliferation in response to HLA-DQ8-glia-alpha1. Gluten-specific memory CD4+ T cells with structurally and functionally conserved TCRs therefore predominate in the disease-affected tissue of patients with HLA-DQ8-mediated CD. Determinants of Gliadin-Specific T Cell Selection in Celiac Disease.,Petersen J, van Bergen J, Loh KL, Kooy-Winkelaar Y, Beringer DX, Thompson A, Bakker SF, Mulder CJ, Ladell K, McLaren JE, Price DA, Rossjohn J, Reid HH, Koning F J Immunol. 2015 May 6. pii: 1500161. PMID:25948817[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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